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Eddgie
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Uranus cloud bands in a C8
      #5423480 - 09/16/12 10:08 AM

I don't know if the person that did these drawings posted them here, but I just saw them.

A month ago or so there was a thread talking about observing details on Neptune and Uranus, and I had mentioned that I have seen features on these planets in the past using my C14.

I had the senses that there may have been some skepticism, because these features are generally very low contrast.

But this link has a drawing that someone made showing detail on Uranus (!) using.. Drum-roll please... An 8" SCT!

Bravo!

Detail on Uranus using an 8" SCT.. Confirmed by Peach image using a C14!


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JimK
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Re: Uranus cloud bands in a C8 new [Re: Eddgie]
      #5423491 - 09/16/12 10:16 AM

Wow! Thanks for posting the link. A new goal to attain for planetary observers. Very impressive.

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John Boudreau
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Re: Uranus cloud bands in a C8 new [Re: Eddgie]
      #5423589 - 09/16/12 11:28 AM

Damian's image was taken with a 685nm longpass filter. One simply cannot confirm a visual observation with an image taken in near-IR light.

Damian (and others including myself), have not been able to capture these features in visible light. Damian mentions that himself in the text accompanying the image that you've linked to.


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stanislas-jean
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Re: Uranus cloud bands in a C8 new [Re: John Boudreau]
      #5423771 - 09/16/12 01:25 PM

We will not retake the forum about Uranus but frankly John if imagers are not showing something in RGB doesnot mean there is nothing in visual fields.
This means only the capability is not enough using the method employed.
Now what is shown in near nir will not differ substantially from the visual field.
We can say an happy coincidence and there are someothers also.
This needs more analysis being not black and white difference.
Stanislas-Jean


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stanislas-jean
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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5423812 - 09/16/12 01:54 PM Attachment (161 downloads)

There are here observations performed with the 150mm refractor that is a little more contrasty than the C8.
Stanislas-Jean


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David Knisely
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Re: Uranus cloud bands in a C8 new [Re: Eddgie]
      #5423825 - 09/16/12 01:59 PM

Yes, but it was taken with a deep red filter (685nm Infrared filter) and was the result of around 45 minutes of taking multiple individual frames (stacked and probably heavily processed to boot). It was also taken with a 14 inch aperture, which would have a much better chance of resolving significant detail on the planet than an 8 inch would. I would be willing to bet that if Damian Peach had used a broad V-band filter, the disk would be pretty blank. There is a BIG difference between visual observing and imaging the planet in the near infrared. Visually, I still do not see anything of note on the disk of Uranus (other than limb darkening), and most people probably won't see a lot more than that either. Clear skies to you.

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Eddgie
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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5423933 - 09/16/12 03:19 PM

And I can say that while not done on the same nights, these drawings (both in the C8 and 6" refractor) show a similar appearence to what I have observed visually using the C14.

I detect them as very slight shading differences between the polar areas and the equitorial areas. A faint contrast difference, but distinct enough that I am sure that I have seen them.

Drawings cannot always convey the subtle nature of these shadings, and sometimes, I think the camera may struggle to render them.

Camera's excel at capturing the smallerst angular detail, but I know from imaging and visual observing that sometimes color contrasts are not well rendered by a camera, and processing can further shift the result.

If the person doing the image cannot see the detail visually (because perhaps they have not tried to see it visually), then how can they know that their processing isn't obscuring some detail? Regisax and other programs can do very funny things to color shading during processing. I know this from direct experience. I don't image much because I am a very avid visual observer, but I do in fact image.

Anyway, I know I have seen it, and I totally believe these drawings and am happy to see that someone else has detected these, and in an aperture that is smaller than I would have thought capable of doing so. And I have every reason to trust these drawings because I have seen Urnaus with similar levels of detail.

Excellent. Really superb. High 5.


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Rick Woods
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Re: Uranus cloud bands in a C8 new [Re: Eddgie]
      #5424356 - 09/16/12 08:36 PM

This surprises me not at all. Good find!

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azure1961p
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Re: Uranus cloud bands in a C8 new [Re: Rick Woods]
      #5424439 - 09/16/12 09:33 PM

I think the very healthy thing that comes out of all this is the controversey itself. And its not newbees versus vets - theres seasoned individuals on both sides of the aisle. The such a strong spirited opinion can be had in both camps sais a lot about the sensitivety of the observers for a fairly *dark* world that appears not so much bigger than Ganymede. Visual planetary observation is clearly a detail oriented pursuit and this - continued topic - is fine testament.

No matter what we may ultimately think, the whole question of real or not has heightened our awareness of this -out-of-the-way - world. I dont think Ill ever look at it again the same frankly, details or not.

The *other* post had some remarks out of bounds but in the interest of discussion and awareness its a winner thread.

My 10 cents.

Pete


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blb
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Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5424472 - 09/16/12 09:50 PM

Personally I did not think that the other thread got out of bounds. Spirted debate sometimes gets a little loud but no blows were exchanged. I thought the mod should never have locked it. I too think we all were learning something that, like you said, will change the way we see Uranus in the future.

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Cotts
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Re: Uranus cloud bands in a C8 new [Re: blb]
      #5424557 - 09/16/12 10:43 PM

It seems Stan is using ever smaller scopes while still seeing detail on Uranus. In the long thread he used a 12" cat, then an 8" SCT and now a 6" refractor.

I agree with some that a highly processed IR image is not proof of Stan's details. There may not ever be any proof of his claims that will satisfy everyone.

Dave


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stanislas-jean
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Re: Uranus cloud bands in a C8 new [Re: Cotts]
      #5424762 - 09/17/12 01:38 AM

You see everybody can have their own opinion, but just opinion.
You see big theories have been raised by imagers with the generation of views with the 685 filter. Now we see others making views with the 742 astronomik the 610 etc.
The 685 may help to get something better with the SNR ratio (to be demonstrated) but what I see visually is the fact that the Uranus contrast levels follow fluctuations, more or less in value and now it seems we are on a good period.
This is the explanation. The planet is not fixed in contrasts, featuring (from an opposition to an other the banding system pattern had changed).
The vision in the R150 is better by the the better scope factor than the mewlon, newtonian and C8 (slightly better).
But this is not prooving this is enough to explain the more easy ability to catch the Uranus pattern except by the fact that contrasts are higher.
So profit of the to_day situation and makes some assessment of the status of to-day.
Stanislas-Jean


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CPellier
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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5424834 - 09/17/12 04:07 AM

The interest of the 685 is that it's imaging features at an atmospheric level where, mainly thanks to the strong absorption of light of the atmosphere in infrared, they attain a good level of contrast.
SNR is not the problem here as it's much more easy to get a good SNR in visible light, where the planet is much brighter. Also, the resolution of telescopes is much better in visible light.
Respecting to the fact that processing can alter the details, this is possible, as well as other things (like collimation). However if a CCD imager is able to detect details in infrared, he should be skillful enough to get them as well in visible light, where imaging is much more easy due to the amount of light available, and to the better resolving power than in infrared.


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stanislas-jean
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Re: Uranus cloud bands in a C8 new [Re: CPellier]
      #5424846 - 09/17/12 04:41 AM

With comparison with the 610 filter which quantified gain the 685 is bringing?
This is interresting to know.
Do we have the idea of which absorption band is involved for the contribution of the image contrast, we have the 619nm (stopped by the 685), the 889nm and after with regards to the chipset sensitivity?
Stanislas-Jean


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stanislas-jean
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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5424848 - 09/17/12 04:44 AM

Collimation indeed is a strong parameter but I found also the sky transparency and steadiness as well.
Sky transparency.
Stanislas-Jean


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CPellier
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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5424873 - 09/17/12 05:29 AM

Quote:

With comparison with the 610 filter which quantified gain the 685 is bringing?
This is interresting to know.
Do we have the idea of which absorption band is involved for the contribution of the image contrast, we have the 619nm (stopped by the 685), the 889nm and after with regards to the chipset sensitivity?
Stanislas-Jean




The RG610 is bringing something like 30-40 % more light, from my last experiences. That's quite a lot. The absorption band is just the broad infrared absorption - from what I have seen this is just like if the CH4 absorption spanned the whole band. After 700 nm we find only narrow peak of emission bands at 750, 820 and 940 but the rest is absorbed.
Here is the spectrum :



Edited by CPellier (09/17/12 05:35 AM)


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stanislas-jean
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Re: Uranus cloud bands in a C8 new [Re: CPellier]
      #5424929 - 09/17/12 07:20 AM

About the cut-off of the chipset,
something around 1050-1100nm?
Are the spectrum compensated with the atmosphere absorption because the absorption bands may be deeper than those shown.
Stanislas-Jean


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CPellier
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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5425000 - 09/17/12 08:48 AM

Yes 1100 nm.
I don't know, about the spectrum... but I have a better one that I will post tonight.


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CPellier
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Re: Uranus cloud bands in a C8 new [Re: CPellier]
      #5425920 - 09/17/12 05:44 PM

Ok so here is the graph I like most, very instructive



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stanislas-jean
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Re: Uranus cloud bands in a C8 new [Re: CPellier]
      #5426658 - 09/18/12 02:12 AM

Sorry, i cannot catch the graph you intent to insert here at the PC screen.
I give you this link which gives data about albedo values for Uranus.
http://arxiv.org/pdf/astro-ph/9810073"%20/
If we consider the absorption bands in cause it may expected some contrast assessments.
Now this should be combined with the respective sensitivity of the eye and the chipset for a certain evaluation approach.
These graphs were published at the time of the support observations and taking into account the relative variability of the planet pattern the assessment will follow these variations.
Stanislas-Jean


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Ira
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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5428041 - 09/18/12 06:42 PM

What magnification was being used in the visual observations?

/Ira


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stanislas-jean
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Re: Uranus cloud bands in a C8 new [Re: Ira]
      #5428614 - 09/19/12 01:31 AM

It's mentionned on the sketch issued on the japanese alpo, 333x. That's make 20min arc at the eyepiece.
Stanislas-Jean


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David Knisely
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Re: Uranus cloud bands in a C8 new [Re: Ira]
      #5428678 - 09/19/12 03:03 AM

Tonight (September 19th, 2012 at about 0500 UT), in my 14 inch Newtonian, I used 384x and 596x under fairly decent seeing (diffraction patterns on nearby stars were sometimes fully visible). I saw no detail on the disk of Uranus other than the ever-present limb darkening, which is pretty much what I have seen with the planet each of the times I have viewed it this year. Clear skies to you.

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stanislas-jean
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Re: Uranus cloud bands in a C8 new [Re: David Knisely]
      #5428727 - 09/19/12 05:24 AM Attachment (64 downloads)

More than a long discussion i enclose here some expectations about contrast potentially reachable on the planet.
Spectrum are not only for the beauty of the curves but can be exploited for assessments.
The green plus yellow surface correspond to the combination of the planet spectrum (compensated) and the eye sensitivity for a mesopic vision. The R band absorption concerns 1-2% of the green and yellow surface. The yellow surface is about half this surface that makes the contrast improved by a ratio 2 times better.
The pink surface corresponds to the combination of the planet spectum and the 618 chipset sensitivity and the use of the 685 filter. It appears that DR and near NIR bands are involved. The contrast level involved can be 3-5 times better than the level got by visual.
All these levels must have to be pondered by the scope factor and the seing level which reduce them.
More than feelings this help to understand more the capability in each kind of observation.
The 610 filter will involve more seeing perturbation and this could be a fact for going to the 685. This is more the bad influence of the seeing that make poor results rather than the filter selection itself.
Now for visual observation the matter is sufficiently quantified.
Stanislas-Jean


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stanislas-jean
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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5431000 - 09/20/12 01:52 PM

For those who are doubting a lot
http://www.astrosurf.com/ubb/Forum3/HTML/035769.html
sorry this is in french but the photo are RGB and R channel.
Not amazing to catch with 150 and 203mm visually.
Please refer to the above curves annd assessments also this is cross checked.
Thanks Edggie to had maintained this forum open.
Stanislas-Jean


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CPellier
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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5431335 - 09/20/12 05:06 PM

Quote:

For those who are doubting a lot




Ok, but I have better images with the same diameter that do not show the belt in R (maybe with the RG610)



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azure1961p
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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5431518 - 09/20/12 07:09 PM

[/qoute]Not amazing to catch with 150 and 203mm visually.




Well if that's not amazing then it'd be amazing for a four inch refractor? Or my 70mm?

Stan what was the aperture of the scope in those Uranus pics at astrosurf? They are interesting.

Pete

Edited by azure1961p (09/20/12 09:26 PM)


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azure1961p
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Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5431522 - 09/20/12 07:13 PM

Mr. Pellier,

The R610 does indeed appear to show atleast a thread of a lighter colored zone by the pole. The other is a little too ambiguous .

Pete


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stanislas-jean
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Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5432044 - 09/21/12 01:38 AM

250mm Pete.
It's not amazing as the contrast on the period get a better level.
Christophe it's time to change, not for me but for all the prvious past great observers (Fournier, Antoniadi, de Vaucouleurs, here O'Meara...).
For imaging we had J Sussenbach who succeed too but not as clear than Fisac, we have others (russians among them).
At present there is D.Peach who performed the best Uranus image with his 355mm but in near NIR, clearer than the 1m.
It last.
Stanislas-Jean


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CPellier
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Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5432116 - 09/21/12 04:22 AM

Quote:

The R610 does indeed appear to show atleast a thread of a lighter colored zone by the pole. The other is a little too ambiguous .




Hi Pete, yes I agree with you.

Quote:

Christophe it's time to change




If I get certain that there is something to see in R, I will say it - and I will get it on images.

Quote:

For imaging we had J Sussenbach who succeed too but not as clear than Fisac, we have others (russians among them).
At present there is D.Peach who performed the best Uranus image with his 355mm but in near NIR, clearer than the 1m.




Among these shots you have IR images - not visible R. Only details in IR are recognized. On images galleries you have also many noisy images that carry false details. You would have to learn to recognize them, especially on Uranus images don't believe everything you see - or only what you want to see... My R above is better than any that will find elswhere.


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stanislas-jean
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Re: Uranus cloud bands in a C8 new [Re: CPellier]
      #5432174 - 09/21/12 06:13 AM

Yes it last.
Stanislas-Jean


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stanislas-jean
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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5447943 - 09/30/12 05:18 AM Attachment (63 downloads)

My last observations got with now the 305mm.
Yesterday evening the images were average to good for a short time (just before the moisture deposition on the vegetation).
Here are the results, not bad for the least as after a 35-40 minuts time the features appearing at the morning limb became more present and those at the evening limb side fade. The dark collar that was present one month ago is not now.
The 2 bands bordering the equatorial zone are the the darkest ones with albedo variation all along to the longitude.
A brightening at the equatorial zone morning side was appearing as shown. There is no planet phase angle at present.
This needs indeed more data for the confirmation and suggest to anybody following this planet to capture data at intervals, each hour for instance in order to show featuring rotating with the planet.
Survey is to be continued.
Stanislas-Jean


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stanislas-jean
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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5454474 - 10/04/12 01:44 AM

Some interresting data here, recent.
Good read.
Stanislas-Jean
http://alpo-j.asahikawa-med.ac.jp/kk12/u120915z.htm
http://alpo-j.asahikawa-med.ac.jp/kk12/u121001z.htm


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David Knisely
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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5454529 - 10/04/12 02:52 AM

I observed Uranus on September 20th, 2012 at around 0500 UT in my 14 inch (355.6mm) aperture f/4.6 Newtonian at from 384x to 596x. I saw nothing on the planet's disk other than limb darkening despite some pretty good seeing (that night, I was able to use up to 961x on the small planetary NGC 6891 in Delphinus to show the object's tiny inner ring and central star). Clear skies to you.

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stanislas-jean
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Re: Uranus cloud bands in a C8 new [Re: David Knisely]
      #5454638 - 10/04/12 07:35 AM

I am sorry.
Stanislas-Jean


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stanislas-jean
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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5462386 - 10/09/12 03:47 PM

Interresting link
http://alpo-j.asahikawa-med.ac.jp/kk12/u121005z.htm
nevertheless that needs more confirmation.
It seems the bands are not purely circular.
To be followed narrowly.
Stanislas-Jean


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azure1961p
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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5463182 - 10/10/12 12:40 AM

Looks like processing artifacts - or rather, over processing. I believe the belts imaged are real but the irregularities are artifacts. I will be following this thinly.

Pete


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stanislas-jean
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Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5463234 - 10/10/12 01:33 AM

Why? because others didn't.
Stanislas-Jean


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John Boudreau
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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5463274 - 10/10/12 02:32 AM

Quote:

Why? because others didn't.
Stanislas-Jean



Stan, I'm sure you've seen limb diffraction effects on images of other planets. The strongest examples would probably be the bright ring that can result on the sunward limb of Mars or Venus, and many times a secondary bright ring occurs just inboard of the outer limb ring. Along with those bright rings there are alternating dark rings. The intensity of this effect varies with seeing effects and with accuracy of focus, along with the size of the scope's aperture (they are much less of a problem with the PDM 1meter, for instance).

When the same effect shows up with a small angular target like Uranus, the secondary bright ring creates an artifact within a large area of the planet's disk and the secondary dark ring can create a dark zone or ring in the center--- in the worst cases, it can appear to look like a poorly defined Fresnel pattern. Also, with the somewhat longer exposures used for such a faint target like Uranus the effect appears softened. In the case of the image you're referencing, it appears to have caused a ripple distortion in the planet's banding.

The same effect also can be seen many times in images of the Galilean moons as they are so small in angular size. To a lesser extent it also affects Mars when the disk gets down to around 4" or so.


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stanislas-jean
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Re: Uranus cloud bands in a C8 new [Re: John Boudreau]
      #5463330 - 10/10/12 05:33 AM

John thanks for your thoughts here.
However, it can be discussed long times about the possibility to get strange results or not.
This is not the debate actually because meaning the fact that for each the method in use is by definition reliable. This is not so easy acquired and demonstrated.
What I note this this the results of the italian observers that raise subtil results, russian as well. Nobody knows what kind of materials they employed (not the scope that is declared, but the environment around the scope).
What i can witness is the fact that albedo variations are present, not only on limbs visually.
What i can bring also, these are reports and publications (issued in public domains now from 2005 and 2007) from Keck teams for Uranus, these comments are about featuring on the disk reported in IR light. This opens the possibility of the collection of albedo variations and for making narrow surveys about without consideration of prior admitted views. It's important to perform as. I am still convinced that against so light contrast variations some "calibration" of the views are to be undertaken. It's matter of reliability and confidence at final.
The visual observation doesnot meet the same kind of problems and can be assessed in parallel ways, the long distanced targets as an example.
Anyway more data and investigated-calibrated methods are needed for a confidence.
Stanislas-Jean


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stanislas-jean
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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5468278 - 10/13/12 12:49 PM Attachment (57 downloads)

Some last report performed on 12th with an excellent 250mm.
A brightening on the temperate belt near the limb.
Weather here is stormy with holes into clouds for short times.
For your perusal.
Stanislas-Jean


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stanislas-jean
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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5484832 - 10/23/12 07:18 AM Attachment (36 downloads)

A small window open in the sky yesterday evening, very stable images even at 25° above horizon and the report here performed with the 150mm cassegrain.
A darker north hemisphere bordered by a faintly lighted equatoriale zone. This appears faintly indeed but cannot be missed.
The sky aperture was too reduced in time for using the 305mm fruitfully but helping for confirmation of the report, but performed for the 150mm results only and not more.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5484951 - 10/23/12 09:44 AM

Nice work.

Have been checking Uranus during every session. For me, this time it appears featureless, but seeing is not cooperating. I have trouble even seeing the limb in sharp focus.

Sunday night, I actually had excellent seeing closer to zenith. I was seeing fairly stable Airy Disk with first ring in the C14, but Uranus was still low over the rooftops, and was unable to really see it without the influence of turbulance.

Disappointing. Was really hoping to get a better view.

I have in fact had poor luch\k with Uranus and Neptune from the city. The best observations were when I was at remote sites with very stable skies, and they were very high in the sky. Most other times, I struggle to them even as very hard disks. Obvious planets, but just not sharply rendered.

Anyway, happy to see that you are getting in some good observations.


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Re: Uranus cloud bands in a C8 new [Re: Eddgie]
      #5485343 - 10/23/12 01:58 PM

Hi Eddgie,
You see in the 6" the images were almost steady quoted 8-9/10 but in the 12" this was only 5-6/10, not bad with regards to the elevation above ground.
In any night there will a moment when the seeing is decreasing sometimes coming to very high good conditions. Here this last just few minuts to, rarely, few hours. The highest elevation is not obligatory the best conditions. Sun set periods and sun rise periods are always good to excellent, after we have the elevation of the planet that is and we must do with.
Yesterday the seeing was quoted on the m6 magnitude star closed to Uranus. At the zenith this was steady purely in the 6". The weather was very humid and the dew deposition high but at a temperature still a little above the dew point sothat the temperature atmosphere equilibrium was at the best possible.
Hope you get and capture something, this shall be also comparisons basis.
Good hope.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5486983 - 10/24/12 01:05 PM Attachment (33 downloads)

Here is the last observations of yesterday with now the 305mm.
The images were pretty good with 435x. I was at the issue of the period more disturrbed by the moisture deposition on the front glass than with seeing (but it failed significantly also at final).
At the evidence the equatorial zone is well lighted and confirmed with the banding structure well evident too. What was surprising me was the polar cap clearer bordered by a thin lighted zone as shown.
Albedo variations are reported into bands but the gain of the W8 filter was faded by the borning moisture deposition. I stopped after.
Nevertheless here are these 2 sketch that surprised me by the observation quality: this means the contrast stronger than say 2 month ago now.
The period is interresting to follow.
For your perusal.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5487353 - 10/24/12 05:15 PM

I need to try again perhaps with more power. Been fighting clouds, but seeing has been good. If I can get some holes tonight, I will wait for them to get to the meridian and give it a shot.

Just got new Baader Hyperion 13mms for use in my binoviewer and will give them a shot...


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Re: Uranus cloud bands in a C8 new [Re: Eddgie]
      #5487988 - 10/25/12 01:39 AM Attachment (35 downloads)

Please try Eddgie, your report will be welcome.
I catched this yesterday evening while posting the observations of 23rd.
The below document is performed by the keck at 1.6µm.
In a certain way a comparison basis, but at 0.619µm the pattern should a little altered because for the upper layers.
Nothing to see in comparison with our small reports.
Good hope.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5488117 - 10/25/12 07:12 AM

Yup.

Had no idea Keck could produce something that amazing.


Pete


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Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5488137 - 10/25/12 07:33 AM

What i note with
the bandind system is not pure circles
some albedo variations are existing into
lot of very small spots present
the twisted north temperate edge of the temperate belt
and so.
Uranus needs a narrow survey.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5488140 - 10/25/12 07:37 AM

I tried again last night. Once again, seeing at zenith was OK, but not great. Had trouble forming an even partial first ring on bright stars.

Uranus was featureless. I am having some transparency issues to though. There seems to he a high humidity haze over my area.


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Re: Uranus cloud bands in a C8 new [Re: Eddgie]
      #5488605 - 10/25/12 01:03 PM

Searching on the net I found this
http://www.planetary.org/blogs/emily-lakdawalla/2012/10221238-uranus-keck-photos.html
The pictures are the same but the performance dates are different.
Good read.
Make trials still Eddgie, the more conspiscious features are the dark north hemiphere and the lighted thin equatorial zone. Question also of light level at the eyepiece, the optimum magnification is to be researched.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5492658 - 10/28/12 05:24 AM Attachment (28 downloads)

An Uranus report of last 27th performed with the 305mm cassegrain.
Only average conditions for the best momments.
The yellow filter was welcome for capturing the overall pattern of the Urannus, but with difficulty.
For your perusal.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5492659 - 10/28/12 05:28 AM

You got some crazy eyes, Stanislas...amazing.

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Re: Uranus cloud bands in a C8 new [Re: Asbytec]
      #5493017 - 10/28/12 11:56 AM

Nothing amazing about it, same story, still not believable.

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Re: Uranus cloud bands in a C8 new [Re: telescopemullet]
      #5493074 - 10/28/12 12:32 PM

thanks for your restricted vocabulary.
Still on stand=by!
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5493461 - 10/28/12 06:03 PM

Stan, your drawings do not show the same curvature of the features as they are in the Keck pictures. In most of your sketches you show the 'bands' to be nearly straight lines and never even remotely as curved as they are in reality. This, plus your continiung failure to show the limb darkening in your sketches, reduces greatly the credibility of your efforts.

Dave


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Re: Uranus cloud bands in a C8 new [Re: Cotts]
      #5493598 - 10/28/12 07:42 PM

The lack of the limb darkening does remove any kind of measure by which to gauge the more subtle features. It makes no good sense to omit this much needed standard as a jumping off point for the finer subtleties. Yes, its a given that the limb shadow is ALWAYS there but being that its ALWAYS needed as a judgement rule, the omission is peculiar.

Pete


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Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5494053 - 10/29/12 03:05 AM

Thanks for your interrest here.
You see the lack of limb darkening can be added, because well seen but this bring what?
If you hope to compare the darkening intensity with some albedo variations noted on "bands", I think you are too demanding.
This is just an intellectual requirement that hope to perform what is not possible to perform.
See the "thickness" of this darkening edge, this take say .2-.3" of arc against a disk of 3.66" of arc where the wider band is about 1-1.2" of arc width, the size of some albedo variations of around 1" of arc and slightly less.
You are too demanding and I think you cannot imagine the difficulty for the least to catch such amount at final.
Showing the limb darkening is peanut against the rest of the sketch. If the credibility is quoted only by this fact I am sorry this is not enough.
However the next documents will have for closing this kind of discussion that doesnot enter for moment of the real subjects that are Uranus presents variabilities and average aperture can be used on this subject.
It is not a matter to make direct comparison with keck results (you see the amount of features collected!).However the document is the reference document and well better than those published recently by some people happy to catch banding with pure circles shape.
But from this to see what can be in common: banding system, band edges not perfectly circular, physically impossible, albedo variations into the pattern, so many clear spots, the polar cap never seen as before that may be the collector of the spots, etc...).
What keck shows if in IR, 1.6µm, what we try to show is visual in red channel where the patterns are not reasonably the same.
Now we try to make something after building a method of observation, visually.
Anybody can be not in agreement, this is a fact and this is, but it cannot be discarded like this so easily.
Anybody also has to make a little effort for trying to understand with pro and cons arguments and not to reject only because not corresponding to their own views or disturbing somebody in high place.
I will continue to issue here some own documents with the demanded limb darkenings necessary, well observed.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5495141 - 10/29/12 06:44 PM

"this bring what?"

Nothing at all Stan. Nothing at all.

Pete

Edited by azure1961p (10/29/12 10:10 PM)


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Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5495432 - 10/29/12 10:27 PM

I know this has been mentioned before, but how far into the infra red might one need visual acuity to see such bands? It's certainly a very rare ability. Eddgie and I, and many others, have failed to notice any features on Uranus while a couple observers must have "crazy eyes" or an active imaginations.

Stanislas mentioned the bands imaged in the far infrared are probably unchanged in the near infra red much closer to and probably right at the limit of human abilities. That argument makes some sense. But, not sketching limb darkening, well...yea, that's a curious omission. It should be there, but that its not might just be observer preference.

So, either Stanislas is seeing these things and truly gifted with "crazy eyes" (even filtered) or has an active imagination. Personally, I don't know which - just understand it's impossible for the vast majority of folks to observe those bands. If it were easy or could be done at all, surely more folks would report such observations.


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Re: Uranus cloud bands in a C8 new [Re: Asbytec]
      #5495460 - 10/29/12 10:43 PM

Norme those Uranian festoons in the Keck images are wild. Its a hellish looking place despite the poker face it presents visually. Those festoons are so incredibly even and symmetrical.

Pete


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Re: Uranus cloud bands in a C8 new [Re: Cotts]
      #5495496 - 10/29/12 11:06 PM

Quote:

Stan, your drawings do not show the same curvature of the features as they are in the Keck pictures. In most of your sketches you show the 'bands' to be nearly straight lines and never even remotely as curved as they are in reality. This, plus your continiung failure to show the limb darkening in your sketches, reduces greatly the credibility of your efforts.

Dave




Dave, I don't agree. Stan's belts appear to me to be curving in the same general way as the Keck pictures. Naturally they're not a perfect match; this is a very difficult observation at best. And, Stan has already said he deliberately doesn't include the limb darkening. I don't understand why that's such a big deal.
Can't anyone accept his observations for what they are - his observations? A couple of others have reported seeing features on Uranus without getting the treatment Stan is getting here.
God help him if he ever reports using Brandons!


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Re: Uranus cloud bands in a C8 new [Re: Rick Woods]
      #5495519 - 10/29/12 11:15 PM Attachment (35 downloads)

Here's a screen grab of a typical Stan rendering of the belts/zones on Uranus. There's virtually zero curvature....

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Re: Uranus cloud bands in a C8 new [Re: Cotts]
      #5495528 - 10/29/12 11:19 PM Attachment (30 downloads)

And here's a screen grab of the Keck IR shot which shows the amount of curvature that should be there assuming the bands/zones Stan is drawing are parallel to the equator of Uranus which they pretty much must be...

No resemblance.


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Re: Uranus cloud bands in a C8 new [Re: Cotts]
      #5495551 - 10/29/12 11:36 PM

Think there might be a slight difference in a Keck IR shot and what can be detected with a backyard scope through an eyepiece .
Seems some just need someone to bash and hate all the time .


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Re: Uranus cloud bands in a C8 new [Re: starrancher]
      #5495650 - 10/30/12 01:03 AM

Pete, hellish, yea....but I would give my left nut (since I don't use it much, anymore) to go there. Heck, to see it that well.

Personally, I cannot account for the differences between keck at 1.6 micrometers and visual at the limit of the human eye.

If anyone can see bands on Uranus, it's an amazing thing. An amazing, rare ability. So many simply cannot, myself included. Best I can make out is limb darkening and some tricky, random albedo changes probably induced by seeing...and trying and really wanting to see bands on Uranus.


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Re: Uranus cloud bands in a C8 new [Re: Asbytec]
      #5495719 - 10/30/12 02:50 AM

I donot understand why people doesnot go to the spectrum given at the begin or the middle of this forum where the possible methane absorption bands appears, in visual field and NIR field with an evaluation of the possible contrast level. That's it. This is more constructive than intellectual observations (Pete) or by strict comparison (feature to feature with Cotts). All are not on the needed wave.
Curvature of banding system, you are too demanding with regards the kind of views we have. I remind here that most of the imagers happy to report banding system shows straight bands also (see the alpo japanese site). We report what we see and it is needed big apparent sizes observed for collecting such apart around the pole that is more evident.
The documents that you see on the forum are performed directly from the eyepiece, they are raw data not improved after at the desk, so some "features" may appear resulting of the paper surface quality or a pen a little too pushed.
We are at an epoch where avery thing must be perfect where this is not possible and not existing.
Festons on the sketch, I never wrote this word, never, this is your imagination that read, not your eyes.
Everything is difficult to collect and the sketch you remind, Cotts, is may be the better one that i did on Uranus and easily performed with excellent sky conditions.
Frankly it stuns me still, after I saw the keck images.
A new time, Images in IR will not be quite the same even with the similar resolution level in visual field (essentially the R channel). Because the interrested atmosphere layers in each are not the same because the atmosphere is scattering the light also.
A new time nobody is able to catch light above say 0.7µm, for convincing you, if this is not done, you can heat a piece of steel at different temperature and test your eyes, you will see. This is not a matter of superhumans but matter of training and lot lot lot of tests. Did you test yourself? Did you test the pertinence of your observational method (even imagers)?
I think not.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: starrancher]
      #5495896 - 10/30/12 09:06 AM

I was referring to the curvature only. I know the detail in the Keck images would not be visible to Stan. My point is his ignoring this curvature (which would be in any bands parallel to Uranus's equator) in his sketches.

Dave


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Re: Uranus cloud bands in a C8 new [Re: Cotts]
      #5496024 - 10/30/12 11:00 AM

There's no hate going on here. He is posting drawings and touts them as being "real." Others can post that what he is drawing is imaginary. That's not hating; it's posting an informed and rationale difference of opinion, which just happens to be well cemented in fact.

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Re: Uranus cloud bands in a C8 new [Re: telescopemullet]
      #5496060 - 10/30/12 11:37 AM

without any argument.
just free opinions.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: Cotts]
      #5496076 - 10/30/12 11:51 AM

Cotts, you should consider the fact that at the eyepiece the apparent size of the planet stands between 20 and 26 minuts of arc only for me and my means. We need 500x to catch Uranus with the same size as the moon viewed with the nake eye.
Try to do some visual tests on a sketch drawn in order to see them with the same angular size (a sketch with bands having the same curvature ratio). You will touch the difficulty that is not intellectual but physical.
It is honestly possible to apraise this curvature near the pole, so difficult at the equator, conditions needs to be perfectly excellent.
We can also draw with curvatures because softwares give the general pattern of the planet as lot of observers does on Mars for instance for the general pattern in use, but, is it well the right method?
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: Cotts]
      #5496363 - 10/30/12 03:16 PM

Quote:

And here's a screen grab of the Keck IR shot which shows the amount of curvature that should be there assuming the bands/zones Stan is drawing are parallel to the equator of Uranus which they pretty much must be...

No resemblance.




I'm sorry, Dave; but I see a strong resemblance.

Edit: I notice there's no limb darkening in the Keck image, either.

Edited by Rick Woods (10/31/12 01:04 AM)


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Re: Uranus cloud bands in a C8 new [Re: telescopemullet]
      #5496384 - 10/30/12 03:32 PM

Observing detail on Uranus is difficult in almost any telescope, especially with apertures smaller than 10 inches. That tiny disk and the powers needed to get it up to a decent size really strains the eye's ability to accurately detect any true detail which might be present without the eye/brain's own "noise" problems messing things up. Over the past 30+ years, I have viewed Uranus in 8 inch, 9.25 inch, 10 inch, 14 inch, 16 inch and 24 inch apertures under seeing conditions which should have allowed the detection of significant detail. Other than the limb darkening (which is quite easy to see even in modest apertures), I have never seen anything else on the disk with any of the previously mentioned telescopes. During recent observations which were triggered by some reports of alleged detail here in the planetary forum, in my 14 inch Newtonian at from 471x to nearly 600x, the disk appeared almost Q-ball smooth with a pleasant light bluish color. I will not dismiss the sudden temporary appearance of detail on that planet from time to time, but at least from my experience, I'm afraid that I am somewhat skeptical about routine visual detection of much band or spot-like detail on Uranus. Clear skies to you.

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Re: Uranus cloud bands in a C8 new [Re: David Knisely]
      #5497235 - 10/31/12 02:27 AM

The main parameter is not the diameter but the contrast transfer ratio for capturing details of low contrasts (probably 1-2% level on the planet, not at the eyepiece).
A new time a 16" will not involve 2 times better the contrast level at the eyepiece with comparison of a 8".
Until your scopes at not characterised (PTV, RMS, etc... for getting a strehl not by a zygo report) this is useless.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5497396 - 10/31/12 08:00 AM

Quote:

The main parameter is not the diameter but the contrast transfer ratio for capturing details of low contrasts (probably 1-2% level on the planet, not at the eyepiece).
A new time a 16" will not involve 2 times better the contrast level at the eyepiece with comparison of a 8".
Until your scopes at not characterised (PTV, RMS, etc... for getting a strehl not by a zygo report) this is useless.
Stanislas-Jean




Sir, are you challenging my observations? The main parameter for determining the visibility of detail *is* the aperture used and only the optical quality may be second to that. Uranus is dim and small, so the more aperture one has, the better off one generally is. As for quality, I know precisely how good the optics are in my instruments (especially my 10 inch and 14 inch Newtonians, as I have actually had their figures measured). The 10 inch f/5.6 (custom figured by Enterprise Optics) has a p-v wavefront error of about 1/19.7 wave sodium light (4.1 nm RMS surface error or 1/67th wave RMS on the wavefront tested over seven zones) and a corresponding Strehl ratio of 0.991. In deference to Mike Lockwood, I have been asked by him not to disclose the precise figures for my 14 inch f/4.6 primary mirror that he refigured for me. However, suffice it to say that they are even better than the accuracy figures for my 10 inch Newtonian's mirrors. Mike refigured both the 14 inch primary and the 80mm (3.15 inch) secondary to a high degree of custom quality. I consider both mirrors in my 14 inch to be as good as can be obtained from *any* custom mirror maker, and they have proved their quality numerous times on the moon, the planets, and the deep-sky. My 10 inch f/5.6 Newtonian has a secondary obstruction of 21.4% of the aperture and my 14 inch f/4.6 Newtonian has an obstruction of 22.5%, so both obstructions are quite modest, especially when compared with some Cassegrain systems. The 16 inch I used to view Uranus with was at Lake Afton Observatory near Wichita, Kansas, and is a research grade Ritchey-Chretien used for research at Wichita State University as well as for viewing by the general public. The 24 inch Starmaster Newtonian I used to view Uranus at the Nebraska Star Party also had custom mirrors in it as well.

Any objection to a negative observation of detail on the disk of Uranus based on some alleged lack of optical quality figures presented is ridiculous. As I have clearly stated, from my observations (especially with this season's observations), I remain skeptical of claims of routine visual sightings of significant detail on the disk of Uranus. This is not "useless" but is a valid observation. Clear skies to you.


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Re: Uranus cloud bands in a C8 new [Re: David Knisely]
      #5497421 - 10/31/12 08:35 AM

This means your 250mm of the described characteristics will be equivalent to 192mm clear perfect diameter. Then you can evaluate the scope transfer contrast ratio by FTM curves and the expected contrast level at the eyepiece which is in this case around the 1% level (for 2% on the planet itself).
This is the situation (the seeing level considered perfect).
Is it possible?
The numbers given may be discussed, especially the actual contrast feature on the planet.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5497743 - 10/31/12 01:04 PM

I believe, that you believe, what you are seeing is detail on Uranus without question. But until Hubble or a ground based telescope shows detail at visual wavelengths similar to what you show, I think you are simply seeing "random albedo changes probably induced by seeing or your vision...and trying and really wanting to see bands on Uranus". This claim is no different than Lowell seeing canals on Mars...extraordinary claims require extraordinary evidence. It has not been provided to satisfy my critical thinking. If you truly are men of science, you must agree with this, your observation is merely a data point that doesn't stand up to logical scrutiny. And the catch is that there are soooooo few other data points with similar result. Like Fox Mulder (X-Files), "I want to believe", but unlike Fox, you haven't convinced me with the evidence presented. Can you not admit that the eye plays tricks with the mind? Truth is, as a visual amature astronomer, I'm rooting for you! But you haven't proved your case.

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telescopemullet
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Re: Uranus cloud bands in a C8 new [Re: t.r.]
      #5497800 - 10/31/12 01:44 PM

Correct sir! I posted a similar argument (a couple of times in fact) back in the now locked thread that was largely ignored and ultimately frowned upon by those who were ignorant of the scientific paradigm. You hit the nail on the head.

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Re: Uranus cloud bands in a C8 new [Re: telescopemullet]
      #5497854 - 10/31/12 02:28 PM

I think gentlemen you are reading with some imagination already fixed before having finishing the read, since the beginning.
You are not in agreement, but of what? We know this now.
Ho! but with which arguments, apart to expose this is impossible to see in IR.
Sorry but this is empty from your side, because you see nothing and this is your main objection, I think in general because this remains always too general and you cannot enter deeper. Please make some efforts.
Stanislas-Jean


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t.r.
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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5497993 - 10/31/12 03:51 PM

Your retort to a logical argument, speaks for itself. The burden of proof and providing supporting evidence for your observations is on you...not those of us who have reams of data to the contrary of what you claim.

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Re: Uranus cloud bands in a C8 new [Re: t.r.]
      #5498024 - 10/31/12 04:15 PM

Apart to show always past photo from hst, lot of years ago, etc... you bring so few.
I am sorry of this, frankly. Now If you want to get some adequate answers that suits you, I guess you read all the posts and those of the forum 3 screens back on the planetary and solar system forums, same subject, "Uranus season is open".
Good read, pick up Mr Mullet with you.
Sorry, the day was very bad as in NYC, but on other fields.
Stanislas-Jean


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David Knisely
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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5498144 - 10/31/12 05:41 PM

stanislas-jean wrote:

Quote:

This means your 250mm of the described characteristics will be equivalent to 192mm clear perfect diameter.




No, the resolution of the instrument is still that of a 250mm clear aperture, so a 10 inch remains a 10 inch. The central obstruction definitely does have an effect, but the common idea of subtracting the secondary's minor axis from the primary diameter is not strictly valid, especially when the obstruction remains fairly modest. Indeed, the light blockage of my 10 inch Newtonian's secondary (2.14 inch minor axis) would make my 10 inch's light gathering ability into an "equivalent" 9.768 inch (248 mm) aperture's light gathering ability. The contrast reduction caused by obstructions in the 20% to 25% range is fairly small and does *not* affect the instrument's resolution. When the obstruction approaches or exceeds 30% is when the central obstruction really starts to impact the contrast of fine low contrast detail (see Suiter's book "Star Testing Astronomical Telescopes" 1st edition, p. 155-157). Most Cassegrain systems have central obstructions in the 29% to 36% range, so for those instruments, that larger secondary obstruction is a very significant factor in reducing the contrast of fine detail.

However, this is all getting well off the topic. If one is looking for a reason why I am seeing little on Uranus with good instruments under halfway decent conditions, well, there is, of course, a possible (and obvious) explanation.....


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Re: Uranus cloud bands in a C8 new [Re: David Knisely]
      #5498171 - 10/31/12 05:58 PM

Stanislas, have you made any of your observations using filters? According to ALPO colored filters are highly recommended in order to see any detail..."Uranus and Neptune: Yellow-green (W12), green (W57), and magenta (W30) filters are recommended on these bluish and greenish planets. Because both planets are much dimmer than the others in the telescope it suggests the Purkinje, Bezold-Brucke, Tritanomalous vision effects may be at work here. Observing these planets is difficult and their blue-greenish color begins to change to a bright blue using moderate to large aperture telescope (12- to 24-inches)". Because of vision limitations, I read that filters are a necessity to have any chance of success.

EDIT: Okay, I do see in one of your old post you use at least one filter #8.

Edited by t.r. (10/31/12 08:10 PM)


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Re: Uranus cloud bands in a C8 new [Re: t.r.]
      #5498310 - 10/31/12 07:17 PM

"Did so!"
"Did not!"
"Did so!"
"Did not!"
"Did so!"
"Did not!"
"Did so!"
"Did not!"

Jeez...


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Re: Uranus cloud bands in a C8 new [Re: David Knisely]
      #5498315 - 10/31/12 07:19 PM

Quote:

Sir, are you challenging my observations?




Well, to be fair, David, you're challenging his.


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telescopemullet
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Re: Uranus cloud bands in a C8 new [Re: Rick Woods]
      #5498340 - 10/31/12 07:39 PM

Correctly so as Stan is drawing nothing more than his imagination.

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Re: Uranus cloud bands in a C8 new [Re: Rick Woods]
      #5498393 - 10/31/12 08:17 PM

Quote:

Quote:

Sir, are you challenging my observations?




Well, to be fair, David, you're challenging his.




No, the poster was not being at all clear about what he was talking about. It appeared that he was challenging me based on the fact that I did not provide the precise figures for the optical quality of my equipment, which is a very bad way to approach things. Clear skies to you.


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Re: Uranus cloud bands in a C8 new [Re: Rick Woods]
      #5498472 - 10/31/12 09:13 PM

Quote:

"Did so!"
"Did not!"
"Did so!"
"Did not!"
"Did so!"
"Did not!"
"Did so!"
"Did not!"

Jeez...







Oh , one more thing .
What the heck is a Mullet ?
Is that some kind of "Achy Breaky" thing ?


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Re: Uranus cloud bands in a C8 new [Re: CPellier]
      #5498495 - 10/31/12 09:31 PM

We all seem to forget that in moments of absolute perfect seeing the eye of someone with 20/15, 20/10 vision will still see detail not caught imaging. You can process all you want but stacking is still stacking and that is an Average of images. There are some of us that can pick out the phase of Venus at its (near) closest point with the naked eye..
And yet in the end we all agree to disagree.


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Re: Uranus cloud bands in a C8 new [Re: orion61]
      #5498635 - 10/31/12 10:52 PM

The 2% contrast on the planet and 1% contrast transfer through a very good scope requires exceptionally perfect eye's with amazing capabilities, such as seeing into the near IR (if the features are present that close to the visual spectrum.)

Especially on a bright, low contrast target like Uranus and at the line frequencies involved. It seems any CO at all would simply wipe out contrast to below the level of ambient noise. Uranus is exceptionally difficult to observe, in my experience, and fluctuations in albedo due to seeing can be seen.

But, if it can be done, it can be done by someone with amazing abilities. I can't do it, certainly not in a 6". Others can't do it in larger scopes. So, "...in the end we all agree to disagree."

I am just not entirely convinced it's even technically possible to visually detect far IR features at those contrast levels in any scope. But, his observation are his observations, as reported, we have to accept them for what they are, as reported. Nothing wrong with skepticism. Some folks do not believe in Big Foot.


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Re: Uranus cloud bands in a C8 new [Re: orion61]
      #5498804 - 11/01/12 12:46 AM

Quote:

We all seem to forget that in moments of absolute perfect seeing the eye of someone with 20/15, 20/10 vision will still see detail not caught imaging. You can process all you want but stacking is still stacking and that is an Average of images. There are some of us that can pick out the phase of Venus at its (near) closest point with the naked eye..
And yet in the end we all agree to disagree.




That's not really applicable here. The simple fact is that specifically on Uranus simple eye versus ccd isn't typical of the comparison you make which is still only partially true. Today's imagers are actually naturally infra red sensitive in a way the eye is not. Indeed, IR CUT filters are often needed to help preserve contrast in a way not affected by infra red. On Uranus then, sans the IR CUT , then the Imaging system has a distinct advantage over the human visual sensitivity. While a dielectric diagonal will negate this, the typical straight thru ccd setups have no such issues.
So while in daylight perhaps there is an advantage in human visual over ccd (though not all people ever) there are distinct imaging sensitivity attributes that no person can compete with.

Pete


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5498815 - 11/01/12 12:59 AM

Quote:

This means your 250mm of the described characteristics will be equivalent to 192mm clear perfect diameter. Then you can evaluate the scope transfer contrast ratio by FTM curves and the expected contrast level at the eyepiece which is in this case around the 1% level (for 2% on the planet itself).
This is the situation (the seeing level considered perfect).
Is it possible?
The numbers given may be discussed, especially the actual contrast feature on the planet.
Stanislas-Jean




I'm a little disappointed with your reply here Stan. You posed the statements that without an observer (we'll call him... Dave) having absolute knowledge of the degree of excellence of his instrument that an argument against your position cannot be mounted. Then, in the face of that an observer (we'll call...) makes all measures of his instruments optics, strehl wave and so on to a decimal point and look what you do - you skipped right around it, made some erroneous remarks about aperture resolution and turned a total blind side to the fact that he substantiated his original claims meeting the requirements you initially stated.

With evasive jukes and dodges like this you make your positions elusive.

Pete


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Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5498920 - 11/01/12 05:06 AM

Making no effort for understanding or try to, no surprise.
David 192mm is not for resolutioon, resolution you have enough. This is for contrast level for the evaluation of a contrast transfer ratio applied on grey line feature. For 1" width this will do 50% ratio so from a 2% level this will do 1% at the eyepiece.
Do you capture? TR as well, for Mr Mullet he is a mullet with his science of 2 pennies, he captures nothing and read nothing but he is so true.
You have all the explanations necessary published on the japanese alpo site with the assessment for the Uranus observation under a mesopic vision because this is a mesopic mode, otherwise you are blinds.
Make some efforts guys, when i am researching something i find a response or a partial one, you, everything has to be brought on a dish with the bended body attitude.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5499000 - 11/01/12 08:02 AM

Again Stan, I DO believe you and others are seeing something...but you cannot and will not concede that it may be illusory. That is the issue. Even O'Meara agrees with this. The science and the numbers are still against you...regardless of your assertion to the contrary. I think this is now at the parallel of arguing politics and religion. Good luck with your future observing program and clear skies.

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Re: Uranus cloud bands in a C8 new [Re: orion61]
      #5499201 - 11/01/12 11:01 AM

Quote:

We all seem to forget that in moments of absolute perfect seeing the eye of someone with 20/15, 20/10 vision will still see detail not caught imaging. You can process all you want but stacking is still stacking and that is an Average of images. There are some of us that can pick out the phase of Venus at its (near) closest point with the naked eye..
And yet in the end we all agree to disagree.




While the stacked result of the selected frames is indeed an average, it's important to note that with proper use of the stacking software only the best frames need be selected for processing and the enhancement techniques applied by an experienced imager will always beat visual given the same seeing conditions. Some processing software even allows manual override of frame selection which while tedious, can further widen the gap between imaging and visual.

For instance, it's a lot easier to detect the Encke Gap with imaging even in less than perfect seeing. Spokes in Saturn's rings were almost routinely imaged during the storm of late 2010 through the first half of 2011. Sub-arcsecond details are reliably recorded on the moons of Jupiter with regularity, again even in less than perfect conditions. And you won't visually see features on Mercury with the consistency of those shown in my avatar, and I've done better than that in recent years.

Besides even if one chooses to discount all that, we also have visual-band HST images of Uranus that are featureless. I don't think many would believe that a skilled observer could see features beyond the range of the HST.

Seems that some simply want to discount seeing and spectral dispersion effects on a small angular target. And nobody is immune to optical illusions, which shouldn't be discounted as a possibility either. Uranus is such a bland target that it may well provide a perfect canvas for observing problems that would normally be overpowered by relatively high contrast features on other planets. Stan isn't the only guy reporting bands, and there have been such observations for many years:

Observations Of The Planet Uranus With The 36-inch Equato...

Back when those Lick observations were made the polar orientation of Uranus was not known. Today observers know the true orientation very accurately. I wonder how the Lick drawings would appear if the observers already knew the planet's true orientation at the time?

BTW--- As has been mentioned by others, the problem here is are there features on Uranus that can be seen routinely even in average seeing? I definitely think not, but I do think at rare times visual spots or other features can occur on Uranus.


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Re: Uranus cloud bands in a C8 new [Re: John Boudreau]
      #5499322 - 11/01/12 12:09 PM

The problem on that kind of subject, John, may I be disapointed by them?
In fact the main channel to conduct conclusions are always the same, all based on a certain experience of problems, very serriously for some and for some others faintaisist even reported by recognised people.
I think on this planet there are also observers, not me, who report something seriously with precautions and cautious with the wording hold (see the BAA section).
The hst images are done in a certain manner, we don't know how. And not sure also that the 1-2% contrast level is well researched or shown. Honestly I don't know apart the views publishedd widely. There are also some others that report variabilities, sometimes level contrasts, so not the landscape you are describing in your post.
Now I donot think the problem can be discarded as you said.
You see in order to be more confortable with some views. Some different assessment methods can be undertaken to see if the question is reachable.
I think very few did this approach in the past and from these recognised people that injured a lot what they cannot approach themselves.
Starting from the investigation on publications on the subject some data were reported in IR and NIR. From it can be expected some contrast levels reachable in the visual field.
We know the fields of the methane absorption bands accessible, the G and R, the G is too confidential.
We know for capturing something on this planet the mesopic vision with its properties needs to be satisfied in terms of resolution contrast levels. We have to-day lot of data published in that fields.
The diffraction laws help today to assess the scope influence in term of degradation, sothat some contrasts at the eyepiece can be asseessed.
Now against these possibibilities it remains our own abilities through tests also that must respect the light levels during observations and the expected feature sizing.
How? Long distance cible observation with known contrast of features lighted by the full moom light only (this was found to be similar on the target).
Test at a Laboratory of yourself with a testing machine (roughly the observation of parallel lines with a sinusoidal grey tone law, the same usable for FTM tests).
The test was conducted until the test pattern having max 2-3% contrats under the similar light level of the planet surface.
If this is not science, amateur, tell me what is science against experience so well recognised.
The conclusion was what: publications gave the conclusion that contrast can be expected at this level, the mesopic vision can support such target, Lab tests and long distance tests demonstrated this ability and now the planet reports are giving what you see.
This is largely better than sp[eaking with experience that means nothing at the 1st approach.
The planet offers the possibility of getting something in R color and under the characteristics given above.
Now, on this alpo japanese site, I guess you to consult ALL the documents because some observers are imaging in pure R channel only and report banding. One observer reported the dark collar near the polar cap in blue channel where the features are recognised to be unexistant.
Artefacts, the method of 90 degree rotation between acquisition were lead aso. My conclusion is artifact when some are unable to make similar at the same level. Views are more lead by ego than by normal analysis of situations.
I am sorry by this architecture given above was already given in past in the forum "uranus season is open".
This is this global system that makes the pertinence not the fuzzy idea of experience.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: t.r.]
      #5499337 - 11/01/12 12:16 PM

TR if you consider the appoach of religion in that debate, I think regarding the results given they are not far from some actuallity reported by very great scopes.
Do you feel that I am on the right way for getting the illumination!
Sorry
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5500292 - 11/02/12 01:11 AM

Quote:

David 192mm is not for resolutioon, resolution you have enough. This is for contrast level for the evaluation of a contrast transfer ratio applied on grey line feature. For 1" width this will do 50% ratio so from a 2% level this will do 1% at the eyepiece.




You are not making yourself clear at all here. What is the size of the central obstruction of your 305 mm Cassegrain and what type of Cassegrain is it? If the central obstruction is significantly more than 25% of the primary's diameter (which I suspect it is), then you are working at much more of a handicap in terms of reduction in contrast of fine features than I ever do. Despite multiple observations, I do not see any markings on the disk of Uranus currently in my 14 inch and never have in any of the other instruments I have used either. I just don't feel there is much to see there. Clear skies to you.


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Re: Uranus cloud bands in a C8 new [Re: David Knisely]
      #5500429 - 11/02/12 05:42 AM Attachment (27 downloads)

Here is the last observation of Uranus performed last 1st November.
Only 10 minuts of sky aperture for this exercise with the 305mm cassegrain under a cristallic sky between cloud formations.
Average images to good on short periods.
It was not possible to get more, the magnification being too low for capturing the albedo variations or brightnings, light glare being too present for the exercise.
Faithfully.
Stanislas


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5500885 - 11/02/12 12:41 PM

And that concludes the thread.

P.


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Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5502397 - 11/03/12 01:09 PM Attachment (43 downloads)

No more reply.
The forum is not concluded Pete.

Here is the observation report for Uranus performed on the 2nd with the 305mm with rather average images.
There are 2 set of sketch (respectively at the same times):

- up: this is the compilation of the raw sketch and the dark edge effect of the planet as it is expected (but observed also in different result).

- down: this the result of the observationnal report performed at the eyepice so the raw data. The edge darkening is forgotten intentionnally because the capture of the features near the limb on the darken ring is problematic, more and more with the increase of seeing level.
The feature collected here are sure.

Globally the up set of drawings being a combination of raw sketch and a disk with a darkening effect. This method may involve un-real feature near the limb, except if a brightening is occuring with a non negligeable intensity, relatively.
This may involve more credibility at the 1st look but with uncertain results.
I prefer to issue still the down set of drawings that are sure and will continue as.

Through this example I would like to highlight the difficulty to draw when the seeing is present more or less and the fact that un-real report can be involved for making credible.
The down set mode will be continued indeed.
Stanislas-Jean


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telescopemullet
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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5502631 - 11/03/12 04:30 PM

Still don't believe you.

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Re: Uranus cloud bands in a C8 new [Re: telescopemullet]
      #5502679 - 11/03/12 05:23 PM

i don't care, peanuts you are dedicated.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5505423 - 11/05/12 01:10 PM Attachment (25 downloads)

Always average conditions with the 305mm.
Nevertheless here is the report of 4th for Uranus.
Nothing different except the brightening on the sun rise limb seen with the W8 filter.
The blue filter use involved something on the edge of the polar cap: a very light dark collar as shown.
Difficult to say with consideration of the conditions, the lighted equatorial zone and the dark north hemisphere being the more conspiscious features.
The report was difficult to acquire.
Stanislas_Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5505427 - 11/05/12 01:15 PM

Quote:


The report was difficult to acquire.





As always, the report is unbelievable, literally.


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5505446 - 11/05/12 01:28 PM

Stanislas, I am still not sure why folks can't replicate your observations. I am not berating you for them, just curious as to how you are managing to observe them. As I understand it, you are using a red filter, something with a long band pass into the IR. Detecting visually 2% contrast on Uranus is simply superhuman. If you have that skill abilities, congratulations.

But, it does seem more folks should be able to replicate your observation with similar filters, apertures, conditions, determination, and skill. If not, then we must be doing something wrong while you're equipment is specifically and exactly tuned to capture them. So, what might observers who cannot report such sightings be doing wrong that robs them of such observations?


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Re: Uranus cloud bands in a C8 new [Re: CPellier]
      #5505538 - 11/05/12 02:32 PM

Quote:

If I get certain that there is something to see in R, I will say it - and I will get it on images.




Hi all, I'm quoting myself :-)) because I have been able to detect the equatorial belt in visible Red light (Astronomik filter) so I'm coming to say it.



With this, I can't argument anymore against drawings made with big telescopes, as they look to show the same belt, among other still controversial things (like nodosities or spots).
Still remain two questions :
- Is really this belt visible with diameter inferior to 10". Contrast is not the only element : the resolving power of the instrument used as well...
- This is the first time that we can establish a certain degree of coherence between drawings and CCD images. Still, drawings made over the last years have no coherence with HST images.


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Re: Uranus cloud bands in a C8 new [Re: CPellier]
      #5505585 - 11/05/12 03:17 PM

Thanks, this is honnest to report this,
1st question: yes this is possible to collect such in moderate aperture. Here with a 150mm refractor also, a C8 exceptionnal, the 203 newtonian and above (have all here at home for the tests). The scope itself is not the good shape. This is is in fact the clear perfect aperture corresponding that is important (explaining in previous posts: D-d with the PTV/ rms involvement, seeing excluded).
-2nd question: you are not the only imager who reported in pure R channel, see the japanese alpo site we have other examples, few in fact but here.
Personnally I will continue to report here.
The brigthtening at the equator sun rise limb is not the 1st time being captured.
The problem is the weather nowadays not cooperating a lot in Paris area. I am waiting colder periods now.
Good hope.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5505635 - 11/05/12 04:05 PM

The idea of resolving it is also interesting. I am guessing any band on Uranus would fall within the bright, low contrast features much like (or more difficult than) Saturn's belts. The MTF is pretty hard on this type of contrast feature with any appreciable CO, but maybe not so at higher frequencies...which this band may be. There is little doubt a mediocre scope wouldn't show it, surely a very high Strehl is an advantage. And there is little doubt a CCD image can capture it, as well: stacked, IR band, enhanced, all that.

Question is, can the human eye detect an already bright, very low contrast feature /after/ contrast transfer from even a perfect optic? Filtering and maybe the fact this might be a high frequency feature, along with appropriate magnification, can produce visual contrast down to about 5% - about the limit of average human ability. Visual detection requires some magnification upwards of 50x to 100x per inch to even begin to have a prayer. The optic, the filter, the magnification, conditions, etc., including high Strehl and super human skill would likely all have to fall into place perfectly for visual...if the scope can indeed present the feature at all. (If not, there is no hope of ever seeing it.)

So, if most others cannot repeat the observation, do they have all or one these factors incorrect? What is the magical formula that puts this feature on the focal plane in such a manner the eye can distinguish it? If others can get this exactly right, there would certainly be more reports and stunned observers.

Now, I have spotted some albedo variations on Ganymede. But, these are bright, high(er) contrast features at higher frequencies, i.e., easier to do visually. I suspect these features fall in the contrast/frequency range where a CO might actually help out past the Dawes limit. Still, it's not easy to see, it does require work, magnification, conditions, etc. CCD images of Ganymede are also very good showing much better resolution. I would bet a C8 could capture Ganymede with some effort. But Uranus is just that much more difficult, everything would have to be pretty much perfect to go much beyond Ganymede's brighter, higher contrast features at it's smaller angular size.

So, how does one optimize the optic to present this feature on the focal plane in a manner the human eye can detect it? And so others can repeat your observations.

Edited by Asbytec (11/05/12 04:06 PM)


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Re: Uranus cloud bands in a C8 new [Re: Asbytec]
      #5505640 - 11/05/12 04:08 PM

Quote:


So, how does one optimize the optic to present this feature on the focal plane in a manner the human eye can detect it? And so others can repeat your observations.




You draw what your imagination thinks it is seeing.


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Re: Uranus cloud bands in a C8 new [Re: telescopemullet]
      #5505646 - 11/05/12 04:12 PM

Quote:

You draw what your imagination thinks it is seeing.




I would not be surprised if I've done that, especially when pushing the envelope to the utter max and maybe beyond. It might be too easy to do often. Not casting any stones.


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Re: Uranus cloud bands in a C8 new [Re: CPellier]
      #5505852 - 11/05/12 07:25 PM

Quote:

Quote:

If I get certain that there is something to see in R, I will say it - and I will get it on images.




Hi all, I'm quoting myself :-)) because I have been able to detect the equatorial belt in visible Red light (Astronomik filter) so I'm coming to say it.



With this, I can't argument anymore against drawings made with big telescopes, as they look to show the same belt, among other still controversial things (like nodosities or spots).
Still remain two questions :
- Is really this belt visible with diameter inferior to 10". Contrast is not the only element : the resolving power of the instrument used as well...
- This is the first time that we can establish a certain degree of coherence between drawings and CCD images. Still, drawings made over the last years have no coherence with HST images.




Hi,

Interesting post. The RGB however may be polluted with Infrared light if you did not use an IR CUT [Baader] filter. My DBK and the DMK both require this in order to filter out the IR that the CCD naturally picks up. If the Astronomik doesnt have this filter, then it is possible you recorded and infrared feature in integrated or RGB light.

Ive never discounted the notion or images of these features on this planet in RGB and Ive seen some good ones.
Unless its specifically blocking IR then...


Norme and Mullet, while the unspoken suggestion here in seeing Uranus features is that only the best observers are capable of such a feat - it could be quite another story. It could be that some observers are prone to observing optical illusions and have greater imaginary "fill-ins" when the eye/brain is starved for stimuli but full on prior suggestion. The Ashen Light sketched by observers is a perfect example of this. And then just like Uranus in infrared it can be said that the ashen light has an infrared signature as well, but as in both cases the ability for the human eye to detect these wavelengths is virtually impossible and what two or three cases exist in humans are in females. So suffice it to say, skillful IR observation is hogwash.

Back on point with Uranus however I personally believe SOME of the belt is in RGB and it isnt exclusively infrared, but how much is open to question. Mr. Pelliers reply as to wether infrared filtering was used would be revealing here.
Until that point is clarified I think this is still too up in the air and it could be a figment of imagination like the ashen light still.

Pete


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Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5505878 - 11/05/12 07:39 PM

Christophe,

It takes a big man to come back and present new evidence contrary to his previous arguments. You have my respect and admiration for your honesty and integrity.

I hope some of the more virulent detractors of Stan's observations will at least step back and consider this new report.


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Re: Uranus cloud bands in a C8 new [Re: Rick Woods]
      #5506279 - 11/06/12 02:08 AM

Thanks Rick for your post.
For replying to others,
Pete the R astronomik filter is pure R channel with no pollution.
Asbystec and Pete, it is not credible to draw something at the limb area when seeing is present. Not only for Uranus but also for other planets. When it is collected a 1" FWHM level (this means statistically an amplitude movement of 1" with a high frequency not visually accessible for the most cases) how it is possible to perceive something conspiscious on that area. This is credible to report what was acquired and not to force what was not. The 2 post was just an execrcise for showing this lack of credibility (think 2% contrast level, on the planet). The idea (as imagers are using each time) of combining 2 screens are not amazing because in fact what are to be collected is a pure featureless disk with limb darkening and a slight low contrasted pattern of features (banding, brightenings). Imagine this compbination. The 2nd calc is indeed more affected by seeing at the limb area.
I don't know if this is a conclusion but this needs more data for progressing away with the brightenings follow-up.
May be with the intensification of the survey spots may appear. So at your eyepieces and your camera for progressing the methods and decrease the shutter times.
Mr Mullet, so out of your shoes.
Rick, I may have so many detractors, this was and is still, but what I note this the credibility of the past observers (with also so many detractors) that merge now more and results from them that may be used with more credibility: this is the main topic and this could be a conclusion that was possible to be issued with Christophe recent issues and from other imagers (italians and russians) that did on the same way, sorry I forget their names on the instant.
Nevertheless Uranus remains so delicate to follow but needs to.
Good hope.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: CPellier]
      #5506280 - 11/06/12 02:08 AM

Imaging (especially in the red and near infrared with image processing) is one thing. Visual observation (i.e. "the Mark-1 eyeball") of Uranus is quite another. We have known about the band structure on Uranus for many decades and few doubt its existence. However, it took deep red images and a lot of processing for Voyager 2 to even begin to detect them. Tri-band imaging from Earth is rarely balanced to even remotely attempt to duplicate the response of the human eye. A digital 35mm SLR operating in standard color mode might come somewhat closer, but even then, with processing, detail would be enhanced over what the eye might normally see. The only way to know what can be seen with the eye is to actually observe Uranus visually with apertures large enough to provide enough resolution and light to allow the eye to easily see what is there. I have done this repeatedly, and I have seen nothing conclusive on the disk at all (except, of course, for limb darkening). A person can put up all the processed red and infrared images they like, but that does not really provide conclusive support for claims of visual band-like detail on the planet. Clear skies to you.

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Re: Uranus cloud bands in a C8 new [Re: David Knisely]
      #5506292 - 11/06/12 02:33 AM

For the R channel you will have not similitude but convergence between methods through results.
In NIR-IR you may have similitude for saying this is not quite the same, convergence is limited.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5506313 - 11/06/12 03:54 AM

Rick : thanks. I'm only interesting in science and objectivity and so if I find I was wrong, I just say it.

Pete :

Quote:

Interesting post. The RGB however may be polluted with Infrared light if you did not use an IR CUT [Baader] filter. My DBK and the DMK both require this in order to filter out the IR that the CCD naturally picks up. If the Astronomik doesnt have this filter, then it is possible you recorded and infrared feature in integrated or RGB light.




Good point. The Astronomik R filter (like G and B) is strongly IR-blocked (blind at 680/690 nm). It even has an orange color quite different from filters like the RG610 Baader (deep red) and it falls completely within the range of the human vision. So this is significant...


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Re: Uranus cloud bands in a C8 new [Re: CPellier]
      #5506402 - 11/06/12 07:22 AM

Thanks. Id seen details before imaged in ccd but the question was always about ir sensitivty. I'm still not at all convinced this can be seen visually but you make a case for its plausability at least in rare cases.

Pete


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Re: Uranus cloud bands in a C8 new [Re: Rick Woods]
      #5506611 - 11/06/12 10:19 AM

Quote:


I hope some of the more virulent detractors of Stan's observations will at least step back and consider this new report.



It ain't going to happen, David's post above explains why. Stan is making this stuff up plain and simple.


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Re: Uranus cloud bands in a C8 new [Re: telescopemullet]
      #5506861 - 11/06/12 12:56 PM

Your opinions gents.
Try to do observations with quantifications, numbers, evaluations rather than feelings where it is excelled so much pseudo-experience on desk corners.
What I note also between R and NIR views this is the close contrast levels and the convergence of the results by the features collected.
Did you capture this when viewing on your desk corner?
Stanislas-Jean
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Re: Uranus cloud bands in a C8 new [Re: telescopemullet]
      #5506945 - 11/06/12 01:50 PM

Quote:

Quote:


I hope some of the more virulent detractors of Stan's observations will at least step back and consider this new report.



It ain't going to happen, David's post above explains why. Stan is making this stuff up plain and simple.




The guy that is really making stuff up is on the ballot today .
How many actually still believe in the falicy is amazing but they don't believe Stan's observations . Go figure .


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Re: Uranus cloud bands in a C8 new [Re: starrancher]
      #5506981 - 11/06/12 02:11 PM

CPellier showed the feature does indeed exist in the visual spectrum, however it might be overwhelmed by higher frequency, unfiltered light and a casual glance. Maybe a red filter can help. But, there is still the problem of it being very low contrast (~1%) made more difficult in any level of seeing and with insufficient magnification. Others should be able to repeat Stanislas observations, especially in larger apertures. Some have, apparently. Best I can observe, unfiltered, is some seeing induced albedo fluctuation and limb darkening.

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Re: Uranus cloud bands in a C8 new [Re: Asbytec]
      #5507063 - 11/06/12 03:19 PM

The use of a 150mm is problematic, possible if a refractor of good facture and not necessary to go to an apo. THis is the PTV/ rms of the optics that win in first.
Don't go to a red filter visually a yellow will be enough with moderate aperture (the W8 or 12).
Personnally a perfect clear aperture of 120mm is enough for capturing. But have a target of 150mm to be more confortable, relatively, this is a mewlon 180 (120mm equivalent), a newton 200 with 20-25% CO (150mm), a good C9.25 (140-150mm), etc...
The newton 200 with excellent optics can do, is less sensitive to seeing and can support 333-400x which is good entry. The rest will depend on yourself.
Try, with average to good nights. You will see.
The refractor that I have here of 150mm is possible (138mm with the yellow filter) with 300-375x, more stable against seeing.
Good hope.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5507975 - 11/07/12 07:09 AM

And while 120mm is the minimum several observers can view through the 1 meter scope
On Picdu midi at 1000x and seenothing. How do you favor a 120mm aperture when the other showeda bald disc?

No matter how you justify if Stan there are glairing didcrepencies. If yiu can see something with a 120mm instrument no matter how subtle it'd be plain as day through that scope.



Pete


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Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5507986 - 11/07/12 07:38 AM

Read the previous posts you will have answers rather to get right for any or all reasons imaginable by you.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5508026 - 11/07/12 08:27 AM Attachment (37 downloads)

Sorry, I've always been lead to believe that any features on Uranus are not visible (when trying to observe in the optical). Personally, I've only ever seen a fuzzy green/blue ball. (similar to the image attached). Am I correct? or is Stanislas onto something? Al.

Al.


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5508150 - 11/07/12 10:23 AM

Quote:

Read the previous posts you will have answers rather to get right for any or all reasons imaginable by you.
Stanislas-Jean




You are insane if you think your telescope is going to provide views that a 1-meter telescope cannot.


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Re: Uranus cloud bands in a C8 new [Re: telescopemullet]
      #5508274 - 11/07/12 12:03 PM

Insane you are if you think any telescope goes away than 2% feature contrast level on the planet. Even a 1km diameter. Tell me which trade name can do, except your mind.
Do you capture, 2%, physically?
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: Hal9000]
      #5508703 - 11/07/12 04:45 PM

Quote:

Personally, I've only ever seen a fuzzy green/blue ball. (similar to the image attached). Am I correct? or is Stanislas onto something?




Well, that does seem to be the question here.
Pick a side, and jump in!


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Re: Uranus cloud bands in a C8 new [Re: Hal9000]
      #5508753 - 11/07/12 05:25 PM

Quote:

Sorry, I've always been lead to believe that any features on Uranus are not visible (when trying to observe in the optical). Personally, I've only ever seen a fuzzy green/blue ball. (similar to the image attached). Am I correct? or is Stanislas onto something? Al.

Al.




Well, I have come to pretty much the same conclusion after observing Uranus over the years in telescopes from 8 inches to 24 inches in aperture. It has been pretty much a blank slate each time as far as significant markings are concerned, although the planet does show some limb darkening right at the edges of the disk. In my 14 inch f/4.6 Newtonian last night, it was a pretty pale bluish ball with the limb darkening but not much else. On a whim, I tried a red filter (Wratten #23a) to see if that might bring out something. That red filter really enhanced the limb darkening, making the planet look like reddish ball with a small brighter almost specular middle, but it also dimmed it to a point where I couldn't use much more than 384x on it and still hope to see much. I guess employing that red filter on dim bluish Uranus will require the use of a much larger scope than my 14 inch. I may try a yellow filter or my NPC Neodymium (minus-violet) filter to see what happens, but based on previous experience, I am not holding out much hope for any belt detail to become visible. Clear skies to you.


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Re: Uranus cloud bands in a C8 new [Re: Hal9000]
      #5508817 - 11/07/12 06:23 PM

Quote:

Personally, I've only ever seen a fuzzy green/blue ball. (similar to the image attached). Am I correct? Al.




Sorry AI, you are wrong. Take a good look at that image you posted. I see a bright equatorial zone .

Pete


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Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5508894 - 11/07/12 07:19 PM

Quote:

Quote:

Personally, I've only ever seen a fuzzy green/blue ball. (similar to the image attached). Am I correct? Al.




Sorry AI, you are wrong. Take a good look at that image you posted. I see a bright equatorial zone .

Pete




Uh, no, AI is pretty much correct. That particular image has the pole of the planet facing roughly towards the sun (it was taken by Voyager 2 back in 1986. The equator would be barely visible only along the limb of the planet close to the terminator. The visible light color image he posted does not show any significant band-like detail, although some representations do show a few very small slightly lighter clouds which would be far below Earth-based resolution. The bands were only seen in highly-processed deep red (methane band) Voyager images. Now, they can also be seen in some deep red and infrared images of the planet taken from Earth. Clear skies to you.


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Re: Uranus cloud bands in a C8 new [Re: David Knisely]
      #5508904 - 11/07/12 07:27 PM

I was kidding Dave.

Pete


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Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5509038 - 11/07/12 09:03 PM

I thought my eyes where deteriorating!
Al


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Re: Uranus cloud bands in a C8 new [Re: Hal9000]
      #5509045 - 11/07/12 09:10 PM Attachment (31 downloads)

I think there may be a bit of this going on... below!

Al.


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Re: Uranus cloud bands in a C8 new [Re: Hal9000]
      #5509060 - 11/07/12 09:20 PM

Hubble photo!

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Re: Uranus cloud bands in a C8 new [Re: Rick Woods]
      #5509306 - 11/08/12 01:38 AM

No from their personnal keck found in minds!
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: David Knisely]
      #5509315 - 11/08/12 01:51 AM Attachment (40 downloads)

Well, I got some of the best seeing and transparency I have had in a long time. Uranus was as tack-sharp as I have seen it recently, and even at only 135x, Oberon was quite easily visible at some distance south of the planet. In fact, it was quite a bit easier to see than Titania was, as both Titania and Ariel were both close to the 'glare" area of the planet (didn't see Umbriel at all). As usual, while the disk was quite well defined with some limb darkening, the disk showed nothing else with certainty. I tried a yellow "minus-violet" filter I have for my refractor, but it didn't reveal anything either. Below is the sketch of what I saw tonight. I was also treated with an outstanding view of the transit of Io across Jupiter, so the seeing was pretty good all across the sky. In fact, at 596x, I could sometimes see the diffraction patterns of stars for more than a second or two, although seeing deteriorated as the wind picked up a little and the temperature went below 40F.

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Re: Uranus cloud bands in a C8 new [Re: David Knisely]
      #5509344 - 11/08/12 02:35 AM

Nice photo, but others do (see the alpo jap site and BAA section).
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5509376 - 11/08/12 04:21 AM

That's a visual sketch.

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Re: Uranus cloud bands in a C8 new [Re: David Knisely]
      #5509387 - 11/08/12 05:03 AM

Quote:

Well, I got some of the best seeing and transparency in a long time. Uranus was as tack-sharp as I have seen it recently




That's a great pic David! Al.


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5510022 - 11/08/12 01:56 PM

It is *not* a photo! It is a drawing I did using my paint software that accurately represents what I saw in the eyepiece (which wasn't hard to do for obvious reasons). Unlike some people's work, it clearly shows the limb darkening and the color of the planet. Clear skies to you.

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Re: Uranus cloud bands in a C8 new [Re: David Knisely]
      #5510134 - 11/08/12 03:29 PM

Quote:

It is *not* a photo! It is a drawing I did using my paint software that accurately represents what I saw in the eyepiece




Fantastic!


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Re: Uranus cloud bands in a C8 new [Re: Hal9000]
      #5510165 - 11/08/12 03:56 PM

Since 2009, Stan the Uranus Man has posted his drawings here: http://alpo-j.asahikawa-med.ac.jp/Latest/Uranus.htm.

Every single one of his drawings have these fictitious features. It will be impossible for him to admit that he is drawing fiction given that he has been doing it for quite some time now and he is firmly rooted in his disbelief. He is a paradigm of one, he is entrenched. Truly there has to be more to astronomy that drawing Uranus to fit one's imagination and self inflate one's ego?


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Re: Uranus cloud bands in a C8 new [Re: telescopemullet]
      #5510429 - 11/08/12 07:27 PM

Quote:

Since 2009, Stan the Uranus Man has posted his drawings here: http://alpo-j.asahikawa-med.ac.jp/Latest/Uranus.htm.

Every single one of his drawings have these fictitious features. It will be impossible for him to admit that he is drawing fiction given that he has been doing it for quite some time now and he is firmly rooted in his disbelief. He is a paradigm of one, he is entrenched. Truly there has to be more to astronomy that drawing Uranus to fit one's imagination and self inflate one's ego?




Mullet,

Why do you persist in badgering Stan so rudely?
I have yet to see you produce anything whatsoever to back up anything you've said. David is at least looking, and going by his own observations. Christophe has come back with evidence of visual detection of the bands. And, people were recording bands on Uranus long before any spacecraft went there.

So, what's your problem? We all know you think Stan is lying. Why don't you just knock it off? Put up or shut up - unless you can offer something to support your contentions, just leave the discussion to the people who are actually discussing it.


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Re: Uranus cloud bands in a C8 new [Re: Asbytec]
      #5510475 - 11/08/12 08:11 PM

What's funny here is that I can almost see a dither of detail in Daves rendering. Its completely illusary but it is persistent. Curiously Uranus itself doesn't do this. Its merely neat clean and gun blue-grey. If its ok on my nights off this weekend ill give this planet a gander but if its like last time it'll be quite blank.

Pete


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Re: Uranus cloud bands in a C8 new [Re: Rick Woods]
      #5510495 - 11/08/12 08:28 PM

Stan continues to draw and perpetuate his fantasy. I can post that I disagree. I haved observed Uranus many times with each of my scopes, what relevance is there that I, like others, continue to see nothing? There is nothing more to add in support of the fact that nothing visually can be seen with the paltry scopes Stan is using. So, Stan will continue to draw, I can continue to post that I think he is making this stuff up.

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Re: Uranus cloud bands in a C8 new [Re: Hal9000]
      #5510526 - 11/08/12 08:49 PM

"I think there may be a bit of this going on... below!

Al."

Now here's a case where the guy went to hell with himself and immersed is expectations in a bath of suggestion - some misinterpreted other purely conjured up and still other just artifacts of the eye brain working too too hard. I really regret in a way we know as much as we do in a small but real way. Up until Mariner flewby and atom bombed the canal theory this had to be a compelling object in a way no other planet can be.
The canals were *seen* by all walks of amateur astronomer. From ones own backyard you could see firsthand the superstructures of another civilization tens of millions of miles across solar space. For these believers in the canals and as a result -observers- this had to be astronomy like none other. Imagine they WERE right and Mariner sent pix of massi e aquaducts and pipelines. Imagine how different our world would be today and how deeply established a Mars/Earthpresence would be. Apollo would have left off exactly at the point mars exploring hit overdrive. Lame skylab - an apollo program wind down and shutoff- wouldve been seen as folly in the face of an uncovered extra terrestrial cibilization. Even politics would have entered the stage... there's and ours.

Oh well.

Pete


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Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5510607 - 11/08/12 09:34 PM

Pete, what size scope is required to "see" canals on Mars? I have never perceived them. I really did want to see detail on Uranus, and it did seem to boil a little in pretty good seeing giving the impression there were albedo changes on the disc. But, they were in no particular or persistent pattern that one could call a feature. IME, anyway. Limb darkening was pretty obvious.

My concern on seeing such features is their very low contrast on the order of 2%, apparently. Those are bright, low contrast features that require some magnification (>50x per inch) to bring them to a scale where the human eye can actually see down to about 5% contrast. That limit might be for an average human eye, and maybe some folks can go deeper down to about 1% contrast. But, that's an exceptional ability. And one would think all other light should be filtered out to have the best chance of enhancing that feature contrast.

http://cityastronomy.com/rez-mag-contrast.htm


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Re: Uranus cloud bands in a C8 new [Re: Rick Woods]
      #5510663 - 11/08/12 10:07 PM

B
Quote:

Quote:

Since 2009, Stan the Uranus Man has posted his drawings here: http://alpo-j.asahikawa-med.ac.jp/Latest/Uranus.htm.

Every single one of his drawings have these fictitious features. It will be impossible for him to admit that he is drawing fiction given that he has been doing it for quite some time now and he is firmly rooted in his disbelief. He is a paradigm of one, he is entrenched. Truly there has to be more to astronomy that drawing Uranus to fit one's imagination and self inflate one's ego?




Mullet,

Why do you persist in badgering Stan so rudely?
I have yet to see you produce anything whatsoever to back up anything you've said. David is at least looking, and going by his own observations. Christophe has come back with evidence of visual detection of the bands. And, people were recording bands on Uranus long before any spacecraft went there.

So, what's your problem? We all know you think Stan is lying. Why don't you just knock it off? Put up or shut up - unless you can offer something to support your contentions, just leave the discussion to the people who are actually discussing it.





Yeah Mullet ! Geez ! Get a life for cryin out loud .


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Re: Uranus cloud bands in a C8 new [Re: starrancher]
      #5510952 - 11/09/12 01:44 AM

All these posts are just polemic and try to make closure of this forum.
They bring nothing consistent, read nothing, produce nothing, report nothing, except David.
Mr Mullet are you jalous?
What a credibility.
Pete you should observe more than you do and analyse with regards to the observations, if you see something. Not learn in books (that is to be done) but not to make entering your theories in your mould. For the other "just to brake the duck legs", that is done but they don't know themselves. Already done.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: Asbytec]
      #5511000 - 11/09/12 03:29 AM

Quote:

Pete, what size scope is required to "see" canals on Mars? I have never perceived them. I really did want to see detail on Uranus, and it did seem to boil a little in pretty good seeing giving the impression there were albedo changes on the disc. But, they were in no particular or persistent pattern that one could call a feature. IME, anyway. Limb darkening was pretty obvious.





Norme,

I know you didn't ask me, but...
I've seen some of the Martian canals very plainly in an 8" reflector, during close oppositions. When they're there, they're not hard to see; many people here have seen them. (I'm talking the broad streaky canals, not the fine spider-web ones; but credible people, [e.g. Robert Richardson, staff astronomer at Mt. Wilson in the 50's], have seen the fine ones in a 6". And he was an "unbeliever" up to that point!)
I've never seen anything close to a detail on Uranus, though.


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Re: Uranus cloud bands in a C8 new [Re: Rick Woods]
      #5511038 - 11/09/12 04:41 AM

Rick, thanks. Interesting. I haven't seen them, not yet.

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Re: Uranus cloud bands in a C8 new [Re: telescopemullet]
      #5511081 - 11/09/12 06:52 AM

Quote:

Since 2009, Stan the Uranus Man has posted his drawings here: http://alpo-j.asahikawa-med.ac.jp/Latest/Uranus.htm.

Every single one of his drawings have these fictitious features. It will be impossible for him to admit that he is drawing fiction given that he has been doing it for quite some time now and he is firmly rooted in his disbelief. He is a paradigm of one, he is entrenched. Truly there has to be more to astronomy that drawing Uranus to fit one's imagination and self inflate one's ego?




Come on folks, lets keep this discussion friendly, insults are not needed and will not be tolerated.

Rich (RLTYS)


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Re: Uranus cloud bands in a C8 new [Re: Rich (RLTYS)]
      #5511147 - 11/09/12 07:53 AM

Sorry Pete it's from your mould.
What is done from me is the worst (under bad conditions) and the best (under excellent conditions).
Be honnest with acuracy.
Now it is your mould for which nothing different in terms of approach can enter into.
Reporting canali here is your mark of un experience, subjects being so different.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5511172 - 11/09/12 08:13 AM

They are identical.

And let me tell you about my "mould". I don't substitute impossible with incredible to end up uncredible. I don't shoot up on prior suggestion overload then have at it. Ifi can't be honest wigh myself and call an observation not happening then I lose any baseline of truth for which to build from. I still want to see enckes and M57s central star in my 8. I may never and banging my head against the wall isn't going to make it any better.

Stan lets look at the established observagion pfofile for what's needed based on your words:

The belts need at least 120mm of clear aperture to be seen well while eight inches is mjnimum if its an obstructed system. BUT if its the 1 meter scope on pic du midi at1000x well sorry aperture and seeing are not ena ling that big wasteful aperture the eay a 12" scope can be utilized.goo yes Hst does show a very pale band with tge same resolution that resolves volcano plumes on Io but hnfortunately not with the efficiency of gour set up since the humsn eye with a 12" cassegrain is surpassing hsts capabilities. Add to this fhe throngs of folks on the japan alpo site who have similar exclusive physics bending capabilities like you and its totally understandable why somone would draw the letter Y across fthe planets face.
Pete

Edited by azure1961p (11/09/12 09:56 AM)


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Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5511608 - 11/09/12 01:05 PM

The problem is not what you wrote
neither a magnification problem
nor a diameter question beyond a threeshold diameter.
Think contrast and apparent size of a feature seen at the eyepiece under a light level.
Any diameter or scope design will not show a contrast beyond the contrast object, say 2% on the planet never higher than this at the eyepiece, never. With the 1m I calculated something as 1.7%, not 2 and above 2.
At any magnification.
The only question is to use a scope (even a 200mm) that transfer the highest possible contrast at the eyepiece.
That's it. The transfer between a 200mm and a 1000mm is not 5times but less than 2.
The question now is to catch 1.7% contrast level feature or 0.85% contrast level.
This is possible, I did the own test on a test machine in a Lab.
Now to get accessible this feature the light level has to be adjusted by the magnification. Personnally this is 0.55mm exit pupill diameter at the eyepiece under a transparent sky. Means 360x with a 200mm.
Make the exercise with FTM curves, different quality optics levels, different central obstructions, etc...
120 mm clear perfect aperture is the case of my 200mm newtonian with 28% CO and PTV5 or the mewlon 180 case.
They show the thin lighted equatoriale zone and the dark north hemisphere honestly. The refractor 150mm of PTV7 shows them a little more distinct not by the gain perfect diameter but by the better image stability.
The 200mm newton is an orion and the refractor an istar, the mewlon 180 is well known. The 305mm is PTV5 and 33% CO is doing around a 175mm perfect diameter.
All these assessments you have through the old posts and a publication issue in the Alpo Japanese site.
Thanks to them.
Think contrast level not resolution a 200mm scope is enough.
Are you able to capture 1-2% levels, this the challenge even for the users of the 1000mm.
There only ONE point where I could failed, this is the assessment of the feature contrasts assessment of 1-2% on this planet.
The problem is that nobody knows or get data about this or keep data somwhere. 1-2%? What is your answer on that levels? The duck is broken legs!
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5511688 - 11/09/12 01:37 PM

The duck is broken legs. Yes and so this is your must.

P.


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Re: Uranus cloud bands in a C8 new [Re: Asbytec]
      #5511955 - 11/09/12 04:35 PM

Quote:

Rick, thanks. Interesting. I haven't seen them, not yet.




Yeah. And, Richardson's account of seeing them in the 6" (in his "Exploring Mars", 1954) was a postscript to his tale of, on a very good night in 1941, seeing Mars through a 6" refractor, and the 60" and 100" reflectors, with nary a canal to be seen. Then, in 1954, he saw them plainly in the same 6" refractor.
It must have been a much more interesting experience back when it was all still an open question! I wonder what the actual necessary conditions are to see them?

Sorry for the digression; now, back to our program.


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Re: Uranus cloud bands in a C8 new [Re: Rick Woods]
      #5512020 - 11/09/12 05:30 PM

Stan it might not be. Five times but its a whole lot more than the value you give it once you factor in the larger image scale at 1000x and the brightness that accompanies a 1 meter scope. At 1000x the eye works a lot less harder to see the dame contrasts. I'm not even factoring in pic du midi seeing versus your padticular location.

Pete


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Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5512624 - 11/10/12 02:12 AM

azure1961p wrote:

Quote:

I still want to see enckes and M57s central star in my 8. I may never and banging my head against the wall isn't going to make it any better.




Well, in an 8 inch, Encke's division is probably not going to be visible due to resolution issues, but I wouldn't give up hope on the central star in M57 in an 8. I saw it quite unexpectedly in my NexStar 9.25 inch SCT one evening from my driveway, so under outstanding conditions and with some patience, it might not be out of the question in an eight inch aperture. As far as seeing definite detail on Uranus is concerned, well, my experience says that probably isn't going to happen (especially in telescopes much smaller than 10 to 12 inches). Even after getting repeated bouts of seeing that was more than good enough (and using a large enough aperture at 14, 16, and 24 inches), I still haven't seen anything on Uranus. I may take an occasional quick look in the future, but for now, I think I have probably had enough of scanning that featureless disk for hints of something which probably wasn't there to begin with. It's pretty much time now to go on to better things. Clear skies to you.


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Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5512665 - 11/10/12 04:18 AM

It's not exact.
1000x makes the apparent size at the eyepiece to be 1 degree (2 times the moon with the nake eye)
500x makes at the eyepiece the size apparent equalling the full moon size.
For 2% contrast feature on the planet, you get 1% at the eyepiece in the 300mm, this will do 1.7% only at the eyepiece in the 1000mm. But at 1000x the eye is not working in good conditions, image too bright and these low contrasted features are covered by the light glare. It is needed say 1700x for getting the best conditions where the light glare is absent and the images not still blurred by the optics. Remain the seeing problem well understood and that apertures need a perfect site with stable atmosphere exceptionnal, FWHM less than 0.1".
So reporting some visual observation with 1000x only means a lot also.
But at final apart the seeing conditions, capturing 1% or 1.7% remains a must.
As a certain example viewing of the encke in a 250 involves a contrast of about 5%, a thin grey line, not black.
On uranus banding is of 1" width lined feature with 1 or 1,7% contrast level.
If this is an help for the approach visually.
An other way can be: draw line on a paper of that level contrast (5% in the word software is possible) and try to see this, show this around you to somebody else, collect the results. If you get few % having seen something, you will have a tendency of abilities. I did also.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5521555 - 11/15/12 04:44 PM Attachment (78 downloads)

Here is the observation of Uranus of last 15th performed with the 305mm cassegrain.
Good to excellent images on the calm times (1-2sec).
The more conspiscious results are given with the use of the W8 filter: brightening on the sun rise limb side on the equatorial zone. The albedo variations are given on the sketch with darkenings on the south edge of the equatoriale zone.
No enough time to show rotation of these features as the local haze became too thick for continuing the observations.

The images were enough good for showing the darkening edge effect on the planet limb.
The magnification of 435x and the sky transparency were optimum for the visual capture of the albedo variations.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5534798 - 11/23/12 02:59 AM Attachment (57 downloads)

Here is the Uranus observations performed with the 305mm with 435x.
The images were just average sometimes poor.
However the present report is produced for your perusal.
This is more here an overalll feeling as the perception was too fugitive.
Unfortunately the sky this evening is not open and this will be for days now.
The south hemisphere seems to be covered by 3 parallel darkenings as shown.
It's to be taken with an extremly care and needs a more consistent evening for confirmation
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5534880 - 11/23/12 05:02 AM

Stanislas, you are "da man," as we say. (It's not derogitory, but a compliment in American slang.)

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Re: Uranus cloud bands in a C8 new [Re: Asbytec]
      #5534977 - 11/23/12 08:03 AM

The last pictures needs to be taken with cautious as this is strange and with the sky limited conditions in use.
But there is the worst and the best that are issue on the forum.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5549818 - 12/02/12 05:13 AM Attachment (51 downloads)

The observations of Uranus last 29th nov.
Average conditions of sky and on a short periods of few minuts.
The brightening on the equatoriale zone is still collected (pay attention of the sense of rotation, no diagonal mirror used).
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5551956 - 12/03/12 12:34 PM Attachment (46 downloads)

Here is the report for Uranus performed on the 2nd december with the 305mm.
Still the brightening on the equatorial zone sunrise side.
South temperate belt seems thick with borderlines darker.
A darkening on the south colar belt bordering the polar regio, on the sunrise side.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5563477 - 12/10/12 01:58 AM Attachment (48 downloads)

Here is the uranus observations of last 8th with a 235mm cassegrain.
Excellent conditions with fixed images on the period.
The brightenings were observed on the sun rise side with 70min time difference.
This shows a reinforcement of the brightening intensity at the issue stopped by clouds and be ginning of sky quality degradation.
Anyway the present report.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5567693 - 12/12/12 02:20 PM Attachment (39 downloads)

An Uranus report for the last 11th performed with the 305mm cassegrain.
Excellent to perfect images at last for a sufficient time for collecting the banding system as shown.
Fixed images during minuts at 18H00UT with 506x.
See the brightenings on the equatorial zone both limb sides.
Banding is triple on the south temperate hemisphere.
1st time I got such quality level images with the 305 on this target.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5568004 - 12/12/12 05:43 PM

How is your optimize testing coming?

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Re: Uranus cloud bands in a C8 new [Re: Asbytec]
      #5568578 - 12/13/12 01:41 AM

For the moment the few nights we have here are just dedicated for this present activity.
We will see later.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5576051 - 12/17/12 05:05 PM Attachment (37 downloads)

Here is my contribution to Uranus observation of last 17th.
I just acquired an old C11 Ultima, tested with excellent results and tried it on the subject.
Images were just average and poor at the observation issue.
This should be considered as a trial, however I submit this material for reporting.
Think the scope is good enough as a medium size for the current survey (estimated to be 150-160mm perfect equivalent aperture which is enough, 175mm for the 305mm currently used).
Anyway, with regards to the target, the equatorial zone was seen fuzzy with 2 brightenings on the equatorial zone and on the south temperate hemisphere at the opposite limb, the polar cap being clearer also.
I think with better images we could go further.
Stanislas-Jean.


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5597805 - 12/31/12 11:45 AM Attachment (29 downloads)

The last probably observation concerning Uranus this year.
This was performed with the 235mm cassegrain and 327-375x magnification under an average sky, transparency and seeing.
Anyway, the brightening at CM 190 degree, sun rise limb remains still present. The contour of this zone is too difficult to show acurately.
I tried to report the grey tone variations as it appeared at the eyepiece during the 2 separate periods.
The time now to transmit to readers and present forumers all my best wishes for the new incoming year,
Stanislas-Jean.


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5600707 - 01/02/13 03:25 AM Attachment (27 downloads)

Here is the observation report for Uranus performed last 1st January.
Average images under a transparent sky with the 280mm cassegrain at 400x.
An Irridium satellite was crossing the disk at 19H40UT (the virtual path) with a light flare each 3-4 sec period.
2 Uranus satellites were suspected.
Stanislas-Jean.


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5606441 - 01/05/13 11:57 AM

Here is a link from the japanese alpo site where a UK observer, David Gray, experienced, reported the presence of a spot on Uranus equatorial zone:
http://alpo-j.asahikawa-med.ac.jp/kk13/u130101z.htm
His drawings are not seemsly oriented as mines.
Interesting reports anyway. Didnot catch this present feature on the same days with the 280mm.
Uranus is quite changing from a period to an other, this is sure.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5617444 - 01/11/13 03:14 PM Attachment (18 downloads)

Here is the Uranus report for 11th january.
A brightening on the equatorial zone as shown (however considerably amplified0
The cassegrain of 280mm was used with 400x under a transparent sky and average good seeings.
Several brightenings at the limbs.
The sketch on the left is the draft performed at the eyepiece and sketch on the right is respecting as possible the albedo ratio between area.
Not bad, the scope can do deeper under better conditions.
Stanislas-Jean.


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5628144 - 01/17/13 01:56 PM Attachment (12 downloads)

Here is the report for Uranus performed last 16th with the Cassegrain 235mm and 375x.
Short time period of 20 min with good images helped me to draw what is given.
It was captured the similar brightenings than those reported last 11th (CM about 70 degree).
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5629826 - 01/18/13 12:03 PM

Stan,
I think you have some streaks on either your eyepieces or objectives. You should never clean fine glass with steel wool!


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Re: Uranus cloud bands in a C8 new [Re: DHurst]
      #5629902 - 01/18/13 12:51 PM Attachment (17 downloads)

Sorry for these bad qualities!
However,
Here is my contribution for Uranus observed last 17th with the cassegrain 280mm and 400x.
Good images sometimes during the period, bad after 17H45UT.

Now the weather becomes cloudy and snowy for long days.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5645485 - 01/27/13 05:00 AM Attachment (36 downloads)

A hole in the sky yesterday, therefore the present report for Uranus is transmitted to you for your attention.
Brightenings are shown by the arrows, still the same brightenings.
Conditions were average with few stable time moments.
There is no festons as it may appear on the sketch on the right that is a representation of the draft sketch (left) with improved contrast level. We think more albedo variations than festons, streaks etc, except the banding system.
Stanislas-Jean


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telescopemullet
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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5650867 - 01/29/13 06:13 PM

Still think you are making all this fantasy up in your head.

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Re: Uranus cloud bands in a C8 new [Re: telescopemullet]
      #5650971 - 01/29/13 07:18 PM

Geez Mullet let it go .

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Gil V
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Re: Uranus cloud bands in a C8 new [Re: starrancher]
      #5651064 - 01/29/13 08:04 PM

I'm kinda liking this thread. Please, sir, can I have some more?

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azure1961p
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Re: Uranus cloud bands in a C8 new [Re: Gil V]
      #5651222 - 01/29/13 09:39 PM

You want WHAT????


Pete


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stanislas-jean
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Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5651535 - 01/30/13 02:05 AM

Not interested with, no concern, this is interesting people on the subject. Now the debate is on and in that circle and with consideration.
Sorry gents.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5651570 - 01/30/13 03:11 AM

I really like this thread and have followed it from the beginning. To be honest I think it's one of the best threads I've read on CN, and a great use of it. One can only enjoy and learn so much from threads covering exactly the same topics being debated by the same people (of which I am one, more or less) again and again and again. Here we have someone making scientific observations of a planet, and other people either pleased to read the observations, or refuting them, sometimes angerly and derisively. I'm sure that some people were angry about those old Mars observations, and those people turned out to be right, the maps were false. Others have dismissed claims which have turned out to be true. Is it possible that Stan has some rare and special visual acuity which allows him to see detail on distant points that most can't see? I think so, but I really have no idea. Maybe he'll be proven right or wrong in his observations sometime, and maybe not, and I'm not sure it really matters. I think both the observations and the debate about them have been interesting and worthwhile, and as an amateur astronomer I find it far more inspiring than most other threads here.

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Re: Uranus cloud bands in a C8 new [Re: mark8888]
      #5651726 - 01/30/13 07:43 AM

For pushing the facts here, this present opposition was prolific with reports from MMr Obukhov, Di Stephano,Gabriele, Yamazaki, Kazemoto,Ikemura, Mogami, Medugno, Peach and Sussenbach for ccd, MMr Gray and Abel for visual including me.
CCD were done in NIR, pure R or RGB channels with features appearing (banding, brightenings).
I think this is enough to demonstrate the capture of features by visual means with results convergent (banding for the least, brightenings for some).
Have a look on the japanese Alpo site for information data.
We will do more next Uranus opposition.
Thanks a lot to every body who read here all the posts, pro or con, and respond to.
What is encouraging was the frequentation for getting observational data on the said japanese site, thanks to the japanese gents for the publications.
More we will be for issuing data, more this will be recognised and consulted.
Good hope.
Thanks Mark for your post, an encouragement.
Stanislas-Jean


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telescopemullet
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Re: Uranus cloud bands in a C8 new [Re: starrancher]
      #5654310 - 01/31/13 01:18 PM

Quote:

Geez Mullet let it go .




No, I will not let it go. This guy sees bands in very small scope every single time he puts Uranus in his eyepiece, regardless of seeing conditions. It is pure fantasy, period.


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Re: Uranus cloud bands in a C8 new [Re: telescopemullet]
      #5654970 - 01/31/13 08:03 PM

.

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Rick Woods
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Re: Uranus cloud bands in a C8 new [Re: telescopemullet]
      #5655389 - 02/01/13 12:29 AM

Quote:

Quote:

Geez Mullet let it go .




No, I will not let it go. This guy sees bands in very small scope every single time he puts Uranus in his eyepiece, regardless of seeing conditions. It is pure fantasy, period.




You're making a quite definite assertion. May we see your proof?


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Re: Uranus cloud bands in a C8 new [Re: mark8888]
      #5655495 - 02/01/13 02:15 AM

The only thing this thread (and the previous one over a year ago) have done is get me out observing Uranus. This was a valuable consequence, but unfortunately, in the end, it amounted to an exercise in frustration. The first time Stan posted (that got my attention anyway) was on the appearance of a possible spot on Uranus in late 2011. I got all excited that finally there might be something visible on the planet, so I pulled my 9.25 inch SCT out to see if something was up. All I saw was what I had seen over the past four decades: a small pale bluish disk devoid of any detail other than the limb darkening and the "visual noise" that shows up at low light levels when viewing dim objects. I eventually pulled out my 14 inch f/4.6 Newtonian to give the planet a more rigorous look at higher power, but still didn't see any spots, bands, or other markings despite a number of viewing sessions under fairly decent viewing conditions.

I put it down to just dumb luck missing a spot that had vanished until I noted all the band-like detail he was showing in his drawings time after time that I didn't get to see even a hint of. After that (and more observations with the 14 inch), I started to have some significant doubts. They re-surfaced in another similar thread about the "Uranus season", when Stan continued to post his drawings that showed significant detail. I had earlier tested things more rigorously with observations in a 24 inch driven Dobsonian at the Nebraska Star Party, where in the pre-dawn hours of one July morning, I managed to again see nothing other than the still smoothly-blank limb-darkened disk of Uranus.

After a few more observations with my 14 inch at powers that should have easily revealed significant detail if present, I have basically given up on seeing any detail on the planet. Despite the larger apertures and higher powers used, Uranus remains the pretty but basically featureless pale bluish ball that it was when I first laid eyes on it in my 8 inch f/7 Newtonian back in the mid 1970's. Back then, the Stratoscope II balloon images of Uranus showed a blank disk, as did my views of Uranus at Lake Afton Observatory in their 16 inch in 1985. Voyager 2 in 1986 also showed (at a much larger scale) that same nearly featureless bluish disk that my 14 inch would continue to show time after time more recently. For these reasons, with my experience, I remain highly skeptical about reports of significant visual detail being routinely seen on that planet. Sorry, but I just don't think there is much of anything there to see. Clear skies to you.


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Re: Uranus cloud bands in a C8 new [Re: David Knisely]
      #5655814 - 02/01/13 08:39 AM

I think something else the Uranus post raises is simply the question: is it OK to question the accuracy of another persons observation? I think the way David provides his take through experiences and results and then probabilities of success in detection , or doubts is fair. You can't fault someone if they have doubts based on their own experiences and at times with substantially larger equipment. It's one thing to say : no you can't and quite another to say: here's what I've found.

I gave it some thought wondering how Id feel if I posted some work and it drew similar : here's what I've found - doubts. I think Id feel bothered even bad but at the same time Id appreciate it more than everyone giving false praise. An attack on honesty is out of bounds but if a fella can't add their own perspective and level of faith or doubt is it even a forum then?

Just sayin...


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Re: Uranus cloud bands in a C8 new [Re: David Knisely]
      #5655976 - 02/01/13 09:56 AM

I have to say after watching the various CN threads re. Uranus with some bemusement – and restraint; and seeing my name come up at times, some response is in order here.

With the “Uranus season is open” thread which had the usual protests with this planet. But worse in my view was the inordinate amount of techno-babble – disregarding the usual psycho-babble. More concerning is the amount of long-distance analysis/diagnosis/assumptions and such of other observers’ observing skills and telescopes: for the record my 415mm f/16 Dall-Kirkham Cassegrain has a 19% central obstruction. Further I have come close to being tarred with the same brush as those who practice poor observing technique, e.g “staring”. After 50+ years experience (1961…. CN title “newbie”...!!) I consider myself pretty experienced and constantly aware of and addressing the many pitfalls of critical observing. ”!!). My planetary work is in the BAA Section archives, many BAA Journals and several authors’ books and elsewhere). Just as this thread was locked here is an extract of what I was on the point of posting:-

With reference to honesty: David Knisley’s remarks regarding Stanilas’, Abel’s and my observations on the ALPO-Japan site “of these three I think Paul Abel’s are worth noting:” “That is refreshingly honest.” Am I to take it that we other two are to be judged less honest because on this occasion we did not ‘qualify’ our drawings with such a statement? If not implying dishonesty then there is some flawed logic here: as for myself on this particular date conditions were such that the need was not felt. There are plenty of examples on ALPO-J and elsewhere where I have indicated a degree of uncertainty as has Stanislas; and there will be many more instances of mine in the archives of BAA planetary sections – 1960s to recent. Actually it used to be said that one should not put a feature on a drawing unless absolutely sure of it. However my own approach is usually to execute an accompanying drawing showing my best impression of any strongly suspected feature. In the hope this may then give some support to any similar independent impression submitted by others. In this case, however, our more confident observations have gone some way to giving Abel the support he hoped for. It is laudable to express doubts, but overdone it can start to look like hedging.

As for techno-babble and it’s like; to give my stand on such I can but quote what W.H. Steavenson said long ago when someone asked him if the Dawes formula could be modified to include unequal double stars [yes, I know it can - e.g. Sidgwick]. After giving a detailed reply he summarised thus: “Personally I am doubtful as to the value of all such formulae. If an observer actually sees an object there is no point in referring to a formula to find out whether he ought to see it; and if he fails to see it no formula will ensure his success.” The telescope not the armchair! It was often said that science proves that the bumble bee is too heavy to fly; of course it does, and very well – no magic or “physics-bending” and guess what – the science was WRONG!!


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Re: Uranus cloud bands in a C8 new [Re: David Knisely]
      #5656026 - 02/01/13 10:22 AM

As said previous post The (f16)D-K has a 19% central obstruction - see here:
http://alpo-j.asahikawa-med.ac.jp/kk12/c121213z.htm

Below I make further points as related recently to Richard Schmude (ALPO)- extract:-

[Just to clarify: when I refer to Uranus 'glare' I mean in relation to the very diaphanos features which require optimum contrast].

Dear Richard, ...... "Astonished to see visual work being sent to the professionals – I commend your courage and good luck with that!

I have had a pretty good run with the planet this apparition, pretty much keeping things to myself. Though I did send an Oct. 16 drawing along with Jupiter and Venus (Oct 19) to ALPO-Japan but for some reason they only posted the Venus one. But my e-mail has been acting up of late. Next decent view I get I will include an apparition summary in the report and send to various that might be interested.

I have to say I am somewhat dismayed at the way some visual observers are tackling the planet. For e.g. submitting relatively detailed drawings in seeing average or worse: I hesitate to even do a drawing unless the seeing is at least Antoniadi II-III, as the very fugitive features require this minimum to be even glimpsed in my experience. Although I might execute one in III-IV with a cautionary note if I felt strongly enough there was something unusual suspected. In the main I virtually never do a drawing of any planet in worse than Antoniadi III

Also I wish they would clearly show the field orientation and not rely on indicating simply S. or N. Pole as there is unavoidable ambiguity here especially after the IAU.
They are seriously devaluing their work with this slack practice (and the seeing issue) in my view and simply giving ammunition to (the many) sceptics. Which I suspect includes a goodly portion of non-achievers seeking to excuse their own shortcomings.

Just as not many can run a 4-minute mile, so it is that few will have the sort of eyesight required to distinguish slight contrasts regardless of the instrumentation applied and even at the monitor!. Though at the same time I suspect that many wash out the very faint features by having too bright an image. Even with the split light path of the binoviewer I find the planet too bright with the 415mm D-K at even x535 in good transparency and resort to the apodizer. In fact in this respect I tackle it more as a DSO; also often using deeper measured breathing which I find works for weak albedo features as well as very faint stars. I further suspect that those using very large instruments (even on mountain tops) get a little ‘power-mad’/cavalier and neglect to respect this issue of glare. I find it better to dim the image to such a degree that some dark-adaption brings it right. Some of my best views have been through thin cloud, or a degree of moonlight or twilight – usually no apodizer.!

In conclusion I have verified that I am very red-sensitive (perhaps freakishly so!) which may well give me an edge with Uranus. This might explain why I could never get away with a red observing light and have used a dim ‘white’ one for well over four decades now......"

Anyone wants to take issue with me on these posts please be aware (with all respect to Stanislas; and having noticed the shameful way some tried to take advantage) that for all my faults with it English is my first (and only) language!

David Gray.


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Re: Uranus cloud bands in a C8 new [Re: David Gray]
      #5656190 - 02/01/13 11:35 AM

David - bravo! Well said, sir!

I don't now if it's been mentioned on any of these Stan-bashing threads, but all the bold contrast he shows is probably exaggerated for clarity. When I draw Mars, my sketches turn out looking like Mars (more or less!), but the contrast in my sketch is far greater than was actually on the planet.
I suspect the details seen on Uranus are far subtler than represented.


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Re: Uranus cloud bands in a C8 new [Re: Rick Woods]
      #5656220 - 02/01/13 12:00 PM

Quote:


I don't now if it's been mentioned on any of these Stan-bashing threads, but all the bold contrast he shows is probably exaggerated for clarity.




That's not the only thing he is exaggerating in his drawings.


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Re: Uranus cloud bands in a C8 new [Re: telescopemullet]
      #5656297 - 02/01/13 12:43 PM

What a wit.

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Re: Uranus cloud bands in a C8 new [Re: David Knisely]
      #5656310 - 02/01/13 12:49 PM

Quote:

The only thing this thread (and the previous one over a year ago) have done is get me out observing Uranus. This was a valuable consequence, but unfortunately, in the end, it amounted to an exercise in frustration. The first time Stan posted (that got my attention anyway) was on the appearance of a possible spot on Uranus in late 2011. I got all excited that finally there might be something visible on the planet, so I pulled my 9.25 inch SCT out to see if something was up. All I saw was what I had seen over the past four decades: a small pale bluish disk devoid of any detail other than the limb darkening and the "visual noise" that shows up at low light levels when viewing dim objects. I eventually pulled out my 14 inch f/4.6 Newtonian to give the planet a more rigorous look at higher power, but still didn't see any spots, bands, or other markings despite a number of viewing sessions under fairly decent viewing conditions.

I put it down to just dumb luck missing a spot that had vanished until I noted all the band-like detail he was showing in his drawings time after time that I didn't get to see even a hint of. After that (and more observations with the 14 inch), I started to have some significant doubts. They re-surfaced in another similar thread about the "Uranus season", when Stan continued to post his drawings that showed significant detail. I had earlier tested things more rigorously with observations in a 24 inch driven Dobsonian at the Nebraska Star Party, where in the pre-dawn hours of one July morning, I managed to again see nothing other than the still smoothly-blank limb-darkened disk of Uranus.

After a few more observations with my 14 inch at powers that should have easily revealed significant detail if present, I have basically given up on seeing any detail on the planet. Despite the larger apertures and higher powers used, Uranus remains the pretty but basically featureless pale bluish ball that it was when I first laid eyes on it in my 8 inch f/7 Newtonian back in the mid 1970's. Back then, the Stratoscope II balloon images of Uranus showed a blank disk, as did my views of Uranus at Lake Afton Observatory in their 16 inch in 1985. Voyager 2 in 1986 also showed (at a much larger scale) that same nearly featureless bluish disk that my 14 inch would continue to show time after time more recently. For these reasons, with my experience, I remain highly skeptical about reports of significant visual detail being routinely seen on that planet. Sorry, but I just don't think there is much of anything there to see. Clear skies to you.




For me, the 150mm refractor sketches confirmed my skepticism.


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Re: Uranus cloud bands in a C8 new [Re: Rick Woods]
      #5656362 - 02/01/13 01:23 PM Attachment (21 downloads)

Thanks Rick,

Yes this is a factor, and one that critics like to jump on and seem to fail to understand that usually a planetary drawing becomes a sort of synthesis of accumulated impressions grabbed during the better moments of definition. Often you cannot see all at once what you have drawn – it becomes a skill to be developed and cherished in all due care. See this for some drawings made in such good conditions where I practically could – in particular Mars from 2007 Dec. 11 my best ever view.
http://alpo-j.asahikawa-med.ac.jp/Latest/Mem_letters.htm

With regard to exaggeration this should be as minimal as possible – it used to be something of a challenge some years back when reporting these with regard possible publication in magazines etc – now we have PCs & the Internet and other factors need considering. I have addressed some of this problem here.
http://alpo-j.asahikawa-med.ac.jp/kk11/u110121z.htm
and, abandoning the computer drawing idea, here:
http://alpo-j.asahikawa-med.ac.jp/kk12/u121212z.htm

Scanners were always a problem with me and now digitally photograph virtually all my stuff (from about 5-10ft) quicker and simpler using SD card. My scans always produced horrendous specular reflections on the graphite particles entailing a lot of‘re-adjustment’/messing with the drawing and stressing me out!

I long ago abandoned using the commonly recommended 2B pencil and found that a good HB was perfectly adequate. I did it myself many years back but now I can’t understand why anybody would take an arsenal of drawing gear to the observatory: an HB and stump is virtually all I need. Long time BAA observer and friend Alan W. Heath has a saying – KISS: Keep It Simple Son! In fact talking to the late Paul Doherty back in 1995 I was gratified to hear that he too had eventually come to using an HB.

With further regard to Uranus other things should be considered in particular size of the outline. Years back I used 25mm diameter, then went to 30mm and recent years I
have found 40mm about right. The BAA’s 50mm, I feel, is a step too far. I constructed their Saturn outlines not the others I will add. Too small and any even slight inadvertent pencil marks gain spurious significance, similarly with paper texture etc. In fact my Uranus drawings are practically all stump ‘painting’ so are pretty much finished at the eyepiece(s). Actually all my planetary drawings (Jupiter largely excepted) are stump-painted, and with Mars I ‘tickle’ in with the HB where needed – thus all are largely finished on site.

Attached is what I send to various who seem to think I take a portable art studio to the observatory!


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Re: Uranus cloud bands in a C8 new [Re: t.r.]
      #5656377 - 02/01/13 01:33 PM Attachment (27 downloads)

This a straightforward assessment.
Still the confusion between contrast transfer and resolution.
There is a tool for explaining this the FTM curves.
Please consider also that the 6" was able to catch the banding pattern, nothing else.
Uranus is mainly under the difficulty of capturing low contrast levels, about the resolution ability we have enough.
What is sure now over the 3 years intensive observation, contrast levels are fluctuing with time, featuring is changing. The contrasts levels turn around 2% maximum, visual channel, and this is the node of the difficulty, 2% on the planet not at the scope exit.
Conditions of observations are crucial and light glaring has to be avoided. Seeing levels must be also well quoted sothat the observation of a close star and its diffraction pattern is to be performed. Under 10/10-6/10 range the observations are practicable, there are always calm times under these 6/10. David exposed very well these points more than me and his valuable experience.
Now for being positionned against an own ability to catch tiny low contrasted features like on Uranus, everybody has the open possibility to visit a Laboratory for assessing their eyes, that I did. If you are courageous you will refer to previous posts of me with the lighting conditions necessary.
This shall be more prolific rather than futile discussions, it will cost you 300 about for making this an afternoon. You will see what is glaring light with measurements with the optician, stress conditions, light accoutumance, etc...
I was dubitative before, pretty confortable now.
Up to you if you want to progress or staying still on outmodel views.
I donot know a telescope that shows a contrast level more than it is on the planet visually, except with using electronic devices.
Now for sketching, sorry for the amplified appearance, we have lot of guys who doesnot catch the 2% level so with such sketch this is lost by advance with 2% percent drawings.
You have all the data well quantified for the observationnal problem quotation.
For conclusion here is the report of the 30th.
Good hope.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5656432 - 02/01/13 02:05 PM

Stan a visit to the eye doctor isn't needed nor is any courage. The fact is through virtually all seeing conditions you have the same features showing. Then you report on "bubbles" and such as well as detailed drawings of clouds on the night time side of Venus - a planet of which people rarely if ever see anything in daylight.

Something's contrast transfer, red sensitivety and such can't explain. Seeing thermal signatures in detail on the night side of Venus is one of those.

Pete


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Re: Uranus cloud bands in a C8 new [Re: David Gray]
      #5656455 - 02/01/13 02:16 PM

David Gray posted:

Quote:

With reference to honesty: David Knisley’s remarks regarding Stanilas’, Abel’s and my observations on the ALPO-Japan site “of these three I think Paul Abel’s are worth noting:” “That is refreshingly honest.” Am I to take it that we other two are to be judged less honest because on this occasion we did not ‘qualify’ our drawings with such a statement?




It is honest in that marginal "detail" on a planet that may be thought of as questionable by the observer is mentioned as being questionable up-front. I can stare at one of my color drawings of Uranus I have done with my paint programs that are deliberately done to show a small but totally blank disk with a little limb darkening and still occasionally "think" I see hints of very faint details coming and going. This is basically the effect of the eye and brain putting in fleeting detail that isn't really there. If I blow up that disk on my monitor, I see that "detail" vanish, as again, I started with a disk that was deliberately made blank. I know of the effect each time I view a small and difficult target, so unless I am absolutely sure that I can repeatedly see some detail, I don't log it as being there. Saying that one may or may not be seeing something is honest and fully understandable. I have glimpsed the "spot" on Ganymede in only a 9.25 inch aperture and when the seeing allows, additional detail on that moon in my 14 inch is visible at the high powers I like to use. When Mars is halfway decently placed for observation, I have done some fairly good drawings of the notable detail I have seen on that planet, some of which I have posted here on Cloudynights. However, even after repeated observations over the many years I have been an amateur astronomer, in apertures from 20 cm to over 60 cm (8 to 24 inches), I have yet to see any detail on the disk or Uranus other than the ever-present limb darkening. That is my honesty and my truth. Clear skies to you.


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Re: Uranus cloud bands in a C8 new [Re: David Knisely]
      #5656573 - 02/01/13 03:19 PM

Quote:

David Gray posted:

Quote:

With reference to honesty: David Knisley’s remarks regarding Stanilas’, Abel’s and my observations on the ALPO-Japan site “of these three I think Paul Abel’s are worth noting:” “That is refreshingly honest.” Am I to take it that we other two are to be judged less honest because on this occasion we did not ‘qualify’ our drawings with such a statement?




It is honest in that marginal "detail" on a planet that may be questionable by the observer is mentioned as being questionable. I can stare at one of my color drawings of Uranus I have done with my paint programs that are deliberately done to show a small but totally blank disk with a little limb darkening and still occasionally "think" I see very faint details coming and going. This is basically the effect of the eye and brain putting in fleeting detail that isn't really there. If I blow up that disk on my monitor, I see that "detail" vanish, as again, I started with a disk that was deliberately made blank. I know of the effect each time I view a small and difficult target, so unless I am absolutely sure that I can repeatedly see some detail, I don't log it as being there. Saying that one may or may not be seeing something is honest and fully understandable. I have glimpsed the "spot" on Ganymede in only a 9.25 inch aperture and when the seeing allows, additional detail on that moon in my 14 inch is visible at the high powers I like to use. When Mars is halfway decently placed for observation, I have done some fairly good drawings of the notable detail I have seen on that planet, some of which I have posted here on Cloudynights. However, even after repeated observations over the many years I have been an amateur astronomer, I have yet to see any detail on the disk or Uranus other than the ever-present limb darkening. That is my honesty and my truth. Clear skies to you.




You appear to have mis or under-read my post somewhat - (pardon its length)!

Yes with a paint programme Corel Draw /Photopaint in my case you can easily produce a a spurious polar cap effect with the right degree of limb-darkening, also spurious bands edging a painted light zone.

I have seen your paint-effort with Uranus some weeks/months back: showing a rather abrupt edge to the limb-darkeng aginst a rather white central area. This suggests to me too bright an image. Assuming very good seeing there should be no definable edge to the limb-darkening: simply shading off toward centre (look at some of the better Jupiter imagery). I fact so elusive some doubt it is there. To see what I mean look at the texturing settings on WinJupos -check and uncheck the shading box. It is often problematical preseving this effect with scanners - even, at times, applying my better method with the digital camera 'scans' I prefer now - but some success with my more recent efforts. (on ALPO-Japan).

I try to be very deliberate in what I say (hence the length) and only ask that it is read with care. But I do not think I gave an impression of questioning your honesty, or how your eyes behave!


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Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5656737 - 02/01/13 04:47 PM

Sorry for the doctor, but it is laboratory activities with measure machines having resolution grids, color channels, known light levels. There is no medecine at the issue, just a quantified status of your own.
Observing venus in daylight is interresting for light glare limitations. There are best moments for observing also.
Ask David Kni.(he said he has on a last post here)for getting a copy of the book "observing moon, planets and comets" by Dale P Cruikshank and Clark R Chapman, you will find all the necessary explanations, in photometry fields especially for the subject. These are evaluations of the situation of the problem but
before last venus elongation, we were with Mr Put, ccdiste, and the results were remarquably convergent, that is practice and actual data collected.
I am sorry but the visual markings also are more contrasty relatively than on Uranus, during day.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: David Knisely]
      #5667152 - 02/07/13 02:00 PM

Quote:

I remain highly skeptical about reports of significant visual detail being routinely seen on that planet. Sorry, but I just don't think there is much of anything there to see.




I am second to that. Despite using 24" Zeiss reflector with excellent optics and in good to calm conditions, I was never able to see any details on Uranus disk, except some smooth brightness decreasing to the edge of the planet disk.

And I am too highly skeptical about all these reports about visibility of distinct details on a dim Uranus 4" disk through 8" SCT.


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Re: Uranus cloud bands in a C8 *DELETED* new [Re: ValeryD]
      #5667553 - 02/07/13 05:45 PM

Post deleted by RLTYS

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Re: Uranus cloud bands in a C8 new [Re: telescopemullet]
      #5667798 - 02/07/13 08:23 PM

Could everyone please keep your comments on you own observations and not criticizing the observations of others.

i.e. everyone please keep things positive or the lock cometh.


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Re: Uranus cloud bands in a C8 new [Re: ValeryD]
      #5668253 - 02/08/13 02:06 AM

Valery, the C8 is not good but excellent.
I had 3 before and was from my use poor to average only.
This one is more than OK. It allowed me to capture 2 times on Mars the high atmosphere electric clouds over the north pole area during march 2012. It allows to see only the fuzzy banding pattern, please refer to the drawings, the refractor achromat being better a little more.
You see the scope is one of the dimension for this subject the observer a second stage and others.
If you consider apos they are very few to allow the capture tiny features of low contrasts. I noted this trouble long time ago. Most of them don't make possible to see feature on Venus or to go deep in low contrasts levels.
The reflectors make this more possible with more accuracy when the optics are excellent.
Now capturing uranus features or venus features depends on your personal equation that can be improved by the observation conditions, especially the lighting conditions because glaring is a great trouble.
Personal equation is working under mesopic conditions that are altered more or less by yourself.
This can be assessed at a laboratory where a staus of your own can be dressed off.
We know the lighting conditions necessary for the optimal conditions. We know the banding sizing of the subject therefore consideing your own status defined you may conlude to some personal abilities.
Not a strict proove but surely something that makes you confortable against the problem that is quoted.
For the moment we get only subjective idea not quoted, not supported by tests, only views experimented or not.
We know now that imagers get features in pure R channel, B for some (the dark collar around the south pole, also catched visually). These channels are visually accessible.
Now, don't know if a fear effect or not, nobody amoung the imager population can state until which contrast level they can capture. Because imaging methods are unproper to measure those contasts levels.
It may be performed long distance tests on calibated targets by imaging in order to study the contrast transfer using a defined scope. For the momment no echo about this kind of approach for testing themselves.
The saga continue but for assessment of the situation it is necessary to practice tests under actual conditions.
R channel can produce around 2% contrast level so few imaged.
Now for conclusion, draw a line of 5% contrast level on light grey paper, this can be done using a word software, and watch this yourself, show this to people in a meeting and make your status result statistics, you will see, well understood the line location being not given at priori.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5672061 - 02/10/13 09:54 AM

Quote:

Valery, the C8 is not good but excellent.
I had 3 before and was from my use poor to average only.
This one is more than OK. It allowed me to capture 2 times on Mars the high atmosphere electric clouds over the north pole area during march 2012. It allows to see only the fuzzy banding pattern, please refer to the drawings, the refractor achromat being better a little more.
You see the scope is one of the dimension for this subject the observer a second stage and others.
If you consider apos they are very few to allow the capture tiny features of low contrasts. I noted this trouble long time ago. Most of them don't make possible to see feature on Venus or to go deep in low contrasts levels.
The reflectors make this more possible with more accuracy when the optics are excellent.
Now capturing uranus features or venus features depends on your personal equation that can be improved n





Yes Stan an excellent Venus scope to be sure . Your sketches of infrared clouds on the night side of Venus was special indeed.

Pete


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Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5673426 - 02/11/13 01:49 AM

Please read carefully the sketch you read for making comments with acurate situation.
There was also lot of tests given through.
Now this is not here the subject, about venus the ashen light never reported in NIR by me, but check also sketches and the few NIR images. Dark features are similar mostly. Thermal activity report of the dark side of venus, pfutt!
Open a new post on that subject I will be.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5681400 - 02/15/13 12:49 PM Attachment (17 downloads)

This shall be the last report for Uranus for this present opposition.
In spite of the planet elevation, the observation was not bad but interresting and for collecting what is shown.
Very faint equatorial zone, brightenings at the sun rise limb, clear south polar cap were still accessible.
This was un-expected in fact, observation conditions were good enough and transprency on the sky good also with average good images mostly.
The survey will start again next july or august as possibly, this shall be interresting to see if the banding pattern will change with the solar exposition of the planet..
Stanislas_Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5690256 - 02/20/13 06:57 AM

Next season hopefully I will also try to see something on Uranus with my 8" SCT and probably 24" observatory cassegrain. Hope to see some details there.

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Re: Uranus cloud bands in a C8 new [Re: leviathan]
      #5690465 - 02/20/13 09:29 AM

Don't hesitate to publish what will be performed at the time, the C8 being, we would say, at the margin of possibility.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5690496 - 02/20/13 09:49 AM

The C8 is not at any margin, nor is the 24 based on observations made by posters here that do not bother with fantasy.

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Re: Uranus cloud bands in a C8 new [Re: telescopemullet]
      #5690672 - 02/20/13 11:28 AM

Actually Pic du Midi had shown nothing as well visually at 1000x.

Pete


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Re: Uranus cloud bands in a C8 new [Re: David Knisely]
      #5690743 - 02/20/13 12:08 PM

Quote:

David Gray posted:

Quote:

With reference to honesty: David Knisley’s remarks regarding Stanilas’, Abel’s and my observations on the ALPO-Japan site “of these three I think Paul Abel’s are worth noting:” “That is refreshingly honest.” Am I to take it that we other two are to be judged less honest because on this occasion we did not ‘qualify’ our drawings with such a statement?




It is honest in that marginal "detail" on a planet that may be thought of as questionable by the observer is mentioned as being questionable up-front. I can stare at one of my color drawings of Uranus I have done with my paint programs that are deliberately done to show a small but totally blank disk with a little limb darkening and still occasionally "think" I see hints of very faint details coming and going. This is basically the effect of the eye and brain putting in fleeting detail that isn't really there. If I blow up that disk on my monitor, I see that "detail" vanish, as again, I started with a disk that was deliberately made blank. I know of the effect each time I view a small and difficult target, so unless I am absolutely sure that I can repeatedly see some detail, I don't log it as being there. Saying that one may or may not be seeing something is honest and fully understandable. I have glimpsed the "spot" on Ganymede in only a 9.25 inch aperture and when the seeing allows, additional detail on that moon in my 14 inch is visible at the high powers I like to use. When Mars is halfway decently placed for observation, I have done some fairly good drawings of the notable detail I have seen on that planet, some of which I have posted here on Cloudynights. However, even after repeated observations over the many years I have been an amateur astronomer, in apertures from 20 cm to over 60 cm (8 to 24 inches), I have yet to see any detail on the disk or Uranus other than the ever-present limb darkening. That is my honesty and my truth. Clear skies to you.




Your computer drawings of Uranus and your eye telling you there are details that you know are not there. I will say again what I said earlier, the features people see on Uranus is no different then the features that Lowell drew on Mars. Our minds try to make patterns from things that don't have any patterns.

That being said I really wish there was something to see on Uranus, but all the photography from observatories and spacecraft really show that is not the case.


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Re: Uranus cloud bands in a C8 new [Re: LivingNDixie]
      #5690974 - 02/20/13 02:03 PM

Why do you settle " feature are not there".
Frankly you dont know and not analyse the situation of the problem difficulty, Pete as well, because you see nothing and repeat what the morning star newspaper report.
You may research at the Harvard Library (free access) reference documents about the subject and this is not what the morning star report every day with knowing very few.
Now the pic du midi has nothing to do because catching 2% contrast level is to be aimed and any scope with its aperture will show less level. If you imagine to make strongly better with the aperture increase diameter you will be disapointed by the gain got. Try in first to catch those levels without a scope under similar lighting conditions this shall be a beginning.
You dont visit an optical laboratory to see where you are actually with your eyes capabilities, but you are sure, of what.
You dont test your scopes and never assess a problem as it is, canali are in your mind.
Frankly since the beginning of this forum you strictly bring nothing but just claim for claiming.
I have something else to perform and prepare for future and left here, not loosing time.
Staanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5691151 - 02/20/13 03:28 PM

Same old song and dance...

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Re: Uranus cloud bands in a C8 new [Re: telescopemullet]
      #5691243 - 02/20/13 04:13 PM

Quote:

Same old song and dance...






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Re: Uranus cloud bands in a C8 new [Re: starrancher]
      #5691262 - 02/20/13 04:26 PM

I still love how Stan continues to favor using a C8 over a 106cm scope on top of the world. So absurd.

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Re: Uranus cloud bands in a C8 new [Re: telescopemullet]
      #5691453 - 02/20/13 06:13 PM

Moderators, please. - like children.

Edited by ZielkeNightsky (02/20/13 06:15 PM)


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Re: Uranus cloud bands in a C8 new [Re: LivingNDixie]
      #5691522 - 02/20/13 06:47 PM

Quote:

Quote:

David Gray posted:

Quote:

With reference to honesty: David Knisley’s remarks regarding Stanilas’, Abel’s and my observations on the ALPO-Japan site “of these three I think Paul Abel’s are worth noting:” “That is refreshingly honest.” Am I to take it that we other two are to be judged less honest because on this occasion we did not ‘qualify’ our drawings with such a statement?




It is honest in that marginal "detail" on a planet that may be thought of as questionable by the observer is mentioned as being questionable up-front. I can stare at one of my color drawings of Uranus I have done with my paint programs that are deliberately done to show a small but totally blank disk with a little limb darkening and still occasionally "think" I see hints of very faint details coming and going. This is basically the effect of the eye and brain putting in fleeting detail that isn't really there. If I blow up that disk on my monitor, I see that "detail" vanish, as again, I started with a disk that was deliberately made blank. I know of the effect each time I view a small and difficult target, so unless I am absolutely sure that I can repeatedly see some detail, I don't log it as being there. Saying that one may or may not be seeing something is honest and fully understandable. I have glimpsed the "spot" on Ganymede in only a 9.25 inch aperture and when the seeing allows, additional detail on that moon in my 14 inch is visible at the high powers I like to use. When Mars is halfway decently placed for observation, I have done some fairly good drawings of the notable detail I have seen on that planet, some of which I have posted here on Cloudynights. However, even after repeated observations over the many years I have been an amateur astronomer, in apertures from 20 cm to over 60 cm (8 to 24 inches), I have yet to see any detail on the disk or Uranus other than the ever-present limb darkening. That is my honesty and my truth. Clear skies to you.




Your computer drawings of Uranus and your eye telling you there are details that you know are not there. I will say again what I said earlier, the features people see on Uranus is no different then the features that Lowell drew on Mars. Our minds try to make patterns from things that don't have any patterns.

That being said I really wish there was something to see on Uranus, but all the photography from observatories and spacecraft really show that is not the case.




Well, there is a little difference between the "canals" and detail on Uranus. With the canals, it was fine mottled detail that actually exists but which the eye/brain tended to merge together to form an apparent linear feature. With Uranus, there just is the eye/brain doing its best to attempt to show a small nearly blank dim bluish disk under difficult conditions. Once you get down to a certain small scale and lower light level, the "noise" from that "organic" detector/processor starts to show up, so you just have to be aware of it. Other than that, the only thing I can say for certain is that, in apertures from eight to 24 inches, I have not ever seen anything on the disk of Uranus at all (other than limb darkening). From all the time I have spent observing the planet under at least halfway decent observing conditions, I just don't feel that there is really anything there to see in the first place. Clear skies to you.


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Re: Uranus cloud bands in a C8 new [Re: ZielkeNightsky]
      #5691755 - 02/20/13 08:59 PM

Quote:

Moderators, please. - like children.




There's nothing to moderate here. Stan is asserting that he favors a C8 over a much larger apeture instrument situated in a locale better suited for viewing than his. I think most rationale, logical, and scientifically minded people would agree his assertion is absurd. We can cast doubts on assertions can we not or is it because stan is far out on a limb and continues with his drawings that his claims are untouchable?

Edited by telescopemullet (02/20/13 10:39 PM)


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Re: Uranus cloud bands in a C8 new [Re: ZielkeNightsky]
      #5691877 - 02/20/13 10:31 PM

Quote:

Moderators, please. - like children.



Lars,

Your post would have more merit if you contributed anything at all to the topic. There is nothing wrong with debate so long as its not pointed or personal . The thread has had its moments but frankly if the most you can add constructively to a thread on low contrast feature detection is parental posturing you might want to self moderate.

Pete

Edited by azure1961p (02/20/13 10:34 PM)


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Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5692105 - 02/21/13 01:52 AM

What is absurd, gents, this is the fact of not analysing a problem and make all your confidence on your own personal eyes that are irrefutable, by definition.
This is not arguments.
You could watch using the 2.5m of Mount Wilson, this shall be same results.
The question is to capture 2% levels around at the red channel.
The people can argue on the personal SNR ratio on the problem but consider also that some can have better (and tested in actual conditions and on long distanced targets).
Remember the fact that imagers also collected in pure R channel the banding pattern and in B channel also. And lot of people trying to capure only in R channel failed also.
It's time to revise judgements about, built on unconcistencies that you believe in.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5692171 - 02/21/13 04:12 AM

I don't want to comment on the detection likelihood here, but there is a recurring theme in observational threads that it is hard to do much scientific confirmation since the ultimate data involved is what appears after the eye-brain perceptual process has done its thing - and it's hard to capture that "image."

But I think there are somewhat rigorous ways to do "blind" tests of perceptual issues - and one way is to change the image in controllable ways and see if the perception - or sketch in this case - tracks that change. In this case I think that just an extra mirror in the path would change the parity of the image so that the diagonal bands would appear to go the opposite way relative to the gibbous phase - and the N/S orientation. I'm not sure if this would work, but for example if you used an erecting diagonal of high quality along with a simple mirror diagonal, the image parity would be opposite and the sketch should reflect that. The diagonal in use would need to be hidden and the focus roughly pre-set so the observer had no indication which was in use.

If the erecting diagonal was not of adequate quality - or something - then this wouldn't work. But my main point is that even if human perception plays a key role in detection, there are still ways to get a handle on whether or not the detection is a true positive, by altering the image in controlled ways unknown to the observer, while at the same time knowing the ground truth orientation of the bands. In Lowell's time there was no ground truth to reference regarding Mars, but in this case there is with respect to Uranus - just as there is with known close doubles - etc.

Frank


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Re: Uranus cloud bands in a C8 new [Re: freestar8n]
      #5692198 - 02/21/13 05:16 AM Attachment (14 downloads)

If you perform such tests over few months this can cover a maximum of situations.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5692313 - 02/21/13 07:54 AM

To All, Lets keep this discussion friendly or I will lock this thread.

Rich (RLTYS)


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5692359 - 02/21/13 08:53 AM

Here is a message passed on to me by the then (2003) BAA Saturn/Uranus/Neptune Section director David Graham from that severe skeptic Willliam Sheehan (“Planets and Perception” etc)


Hello David - Bill Sheehan was at Lick this summer to observe Mars but I also persuaded him to have a look at Saturn. I will relay his drawing for you to see. I intend to put it in the JBAA in due course.
All the best,
David
----- Original Message -----
From: Debb & Bill Sheehan
To: 'Dave Graham'
Sent: Monday, November 24, 2003 1:02 AM
Subject: RE: Saturn
Hi, Dave,
Thanks for the condolences, which I passed along to the rest of the family.
The Saturn drawing shows detail I was sure of – and within the limits of my artistic ability. It’s a tough object to draw because we think in terms of straight lines and Saturn’s all curves. The magnification used was 655x.
I did look at Uranus with the Lick refractor, since it wasn’t far from Mars and was easy to find, and had the distinct impression that there was a dark equatorial belt, which I thought was peculiar since one is used to seeing bright equatorial zones on the Giant Planets. You can pass along to David Gray my confirmation and also my high esteem for his observational and artistic abilities.
[bold mine]
Hope to see you next year as I’m likely going to be in the British Isles at some point around the time of the Venus transit.
Yours, ever,
Bill


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Re: Uranus cloud bands in a C8 new [Re: David Gray]
      #5692379 - 02/21/13 09:09 AM

This is from a pm recently to Rick Woods (Hi Rick!)

Here is a link to a NASA document see especially the chapter ‘Why Image Uranus’ by Belton & Vescelus page 299 (pdf page 28), which has some pertinent comments re. visual and Stratoscope II.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19770075072_1977075072.pdf

In time (maybe next apparition) I may post something in detail pointing out what I consider to be the optimum requirements for getting at said reality. It is a long list and I can see the protests now – why so much bother to see so little; but my answer will be it is the only way to get to the bottom of it! I can’t help knowing which way the banding is oriented and if I am suffering from illusion and it is in the main consistent with this angle. So this only leaves two factors: I am fooling myself or being grossly dishonest.

I can say something about seeing what one wants to see from my early observing days1961 on:

Mars: I was so beguiled by those Lowell spider-web canal drawings that when my 10” Newtonian came along (1964/me age 20) I eagerly anticipated the 1965, albeit alphelic, opposition; and was gutted to only see relatively disparate irregular well-contrasted features and a few rather coarse linear features. In short I was desperate to see these ‘webs’, but all my wishful thinking would not put them there in any kind of seeing and pretty much left Mars alone till 1988 – BAA Mars director Richard McKim can attest to this!


Uranus: here I was expecting to see a green/blue smaller version of Jupiter (I think some do now!) after seeing a picture in a book at school c.1955; also I knew nothing of the unusual tilt. My first good views in March 1965 irritatingly kept giving a north/south dusky band which I finally decided to draw in the 1966 apparition then left it alone till 1969 when I got presumably an EZ and two narrowish belts: March/April . With it steadily going south in subsequent years and apart from a good view in Dec. 1977 left it alone till 1985 (still v. low in S.) and have followed it since.


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Re: Uranus cloud bands in a C8 new [Re: David Gray]
      #5692380 - 02/21/13 09:12 AM

Interresting and instructive: what we collected also.
Thanks David.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5692443 - 02/21/13 09:59 AM Attachment (10 downloads)

Thanks Stan,

Extract from a message just too late for the locked “Uranus Season......” thread

[Voyager 2]:
Similarly [to Stratoscope II] I keep seeing reproductions of the Voyager polar view with captions such as “….. adjusted as it might appear to the eye”….!! Whether on the monitor or printed page I feel we need to view these with the same caution we should be applying at the eyepiece.

“Adjusted to match what the eye sees”: now there is a can of worms. Whose eye – one of the team, someone passing by, the canteen maid – hopefully those with at least “normal” vision to be serious? Conceivably “normal” falls short of cutting it with this planet; and so many abuse their eyes – health-wise, diet-wise and otherwise (monitor-wise?)!


Not sure how it will come out but attached is a 1993 letter from the late Andy Hollis director of the BAA Asteroid & Remote Planets Section.


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Re: Uranus cloud bands in a C8 new [Re: David Gray]
      #5692488 - 02/21/13 10:33 AM

Thank you for interesting postings, David !

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azure1961p
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Re: Uranus cloud bands in a C8 new [Re: leviathan]
      #5692631 - 02/21/13 12:17 PM

All wonderful accounts but that still doesn't bring any substantiation to belts drawn in even mediocre seeing with an 8" sct and a 6" refractor with as much regularity as viewing Syrtis Major. It is difficult for most anyone to believe regular (every time a man observes) that not only are eq belts observed but temperate polar details, "bubbles" (Stan's words) or giant scalloped voids in these belt regions not to mention conspicuous white spots - and all in the confines of a few months - not decades.

David I highly doubt anyone has doubts your work. I know Im a fan - particularly on your Galilean moon drawings. The impression that is under question here is the availability of such things through modest instruments bordering on small with regularity unwavering and steady.

Pete

Edited by azure1961p (02/21/13 12:19 PM)


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telescopemullet
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Re: Uranus cloud bands in a C8 new [Re: David Gray]
      #5692640 - 02/21/13 12:22 PM

Quote:


I did look at Uranus with the Lick refractor, since it wasn’t far from Mars and was easy to find, and had the distinct impression that there was a dark equatorial belt,




The above observer was using a 36-inch (assuming the referenced Lick refractor does indeed mean The Lick Refractor)and he stated he was given the "impression" of a belt. He did not write that he saw a belt(s), big difference.

Compare this to stan who sees banding 100% of the time no matter what the conditions is scopes of very small size.


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David Gray
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Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5692696 - 02/21/13 12:57 PM

"All wonderful accounts but that still doesn't bring any substantiation to belts drawn in even mediocre seeing with an 8" sct and a 6" refractor with as much regularity as viewing Syrtis Major. It is difficult for most anyone to believe regular (every time a man observes)"

Yes I know this thread's specific is 8" SCT (my 10" Newt comes close)but it concerns me when it is claimed that there is "nothing to see" full stop - to me: bland yes, blank no! I will check it out next apparition with a 6" off-axis stop.

I do not know if it is everytime Stan observes certainly not with me; but I only report views in good seeing. However I did endure with bad-seeing views this apparition on some nights to check out possible illusions and had some interesting impressions that may cheer the doubters! This needs more follow up and hope to post my findings next apparition.


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Re: Uranus cloud bands in a C8 new [Re: telescopemullet]
      #5692697 - 02/21/13 12:57 PM

When you will understand something physical, we will continue, this was answered here before.
Pete, white spots etc... mean like black cats and wording matters a game from you.
We are in the very light grey tones fields.
Read again the posts since the beginning and answer the questions raised, if you wish.
Please consider that all scopes in use were characterised, seeing quoted and you know the conditions well assessed and tested.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5692738 - 02/21/13 01:13 PM

I think that a lot also depends on the experience of observer. Many people only see 2 or 3 belts on Jupiter at a first time, then they start to see polar caps, then festons, ovals and other small details. I mean it comes with experience. And you also need to know where to look to see it.

I honestly observed Uranus only several times. And all critics here should observe it at least as many times as Stan and David did to say that there's nothing to look at. IMHO


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David Gray
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Re: Uranus cloud bands in a C8 new [Re: telescopemullet]
      #5692761 - 02/21/13 01:25 PM

Yes it was indeed the 36" refractor. Perhaps if he had thought to dim the image he may have seen even more! A factor that I suspect those using large and very large telescopes need to address (covered in an earler post of mine -page 10)

David Graham used that very same 36" to look at Saturn in 1995 and told me that all (very experienced) observers present found no difference in intensity twixt the n & s halves of the EZ. But it was established with certainly there was a marked difference also to Hubble - I got it on 57 nights! This was obviously due to an extremlely over-bright image in the 36" washing out the differences.

Not Uranus I know but the very weak features here are easily lost in 'glare'. As the planet climbs higher each year I am finding it too bright in good transparency even with the split light path of the binoviewer and x535 - often resorting to the apodizer; the features are that weak.
See also my earler post to Azure61p.


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Re: Uranus cloud bands in a C8 new [Re: telescopemullet]
      #5692804 - 02/21/13 01:48 PM

"He did not write that he saw a belt(s), big difference."

I lost this bit somewhere in my editing - my response:

When a guy like Sheehan commits to such a remark maybe the difference is not that great.

He was also there in 1995 with David Graham and David told me that he and a couple of others were getting detail on Uranus (the 36") and Sheehan refused to look as he said they had influenced him....!!


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stanislas-jean
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Re: Uranus cloud bands in a C8 new [Re: leviathan]
      #5692830 - 02/21/13 02:03 PM Attachment (17 downloads)

May I re-issue the following tablesheet already given, "the scope factor".
This express the contrast transfer of a characterised scope for features as line with a given width (assimilited as banding).
The improvement bring by the diameter is expressed for 2 hypothesis:
left column transfer ratio considering the FTM evolution with a sinusoidal pattern
right column transfer ratio considering the same but with a patern of black and white lines (assimilited to banding also).
The transfer ratio never reach the ratio 1 but less.
For a 12" sct (as mine) the ratio transfer is 50% for a 24" 74% and for the famous 40" not more than 87%.
THis mean having a 2% on the planet, at the eyepiece it is just necessary to combine the 2% with the ratio transfer to get the contrast at the eyepiece.
Therefore if the personal equation of the observer is not able to assum 2% for the least, bad hope for capturing something and good hope for declaring Uranus disk is featureless.
Anybody as also said can visit a lab for testing his personnal equation.
Just do it Pete.
The results of the tablesheet was well tested also on the sky with scopes from R150mm until the 12" cassegrain and also, you remember under the schematic drawing for testing given 4 or 5 posts above (some comments about?).
According me any problem needs to be well quoted to see where we are. It's done.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5693831 - 02/22/13 12:11 AM

There you go again Stan. No I'm not going to saturate my preconceived notions on lists, and figures and percentages. There's a lot to be said for keeping the slate clean so to speak. I haven't given up on Uranus much as I haven't given up on the current white spots on Jupiter with my 8" in mediocre seeing. In the same token Im certain beyond anything it isn't going to show with calendar regularity. Information is good in locating threshold detail but it can also be a bad thing in excess. It's a fine line .

David G. Thanks for your comments. Funny enough I just bought a Sheehan book on the planets a couple hours ago on iBooks.'

Pete


Edited by azure1961p (02/22/13 12:14 AM)


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stanislas-jean
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Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5693913 - 02/22/13 01:36 AM

May I suggest the practice by you of the tests drawn above, this will help you to locate your personal equation and for knowing where you are in face of the Uranus problem.
This shall be quantified in an other manner than through just words.
Good hope.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5694250 - 02/22/13 09:17 AM

Lol I don't have a problem with Uranus.

Cheers.

Pete


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telescopemullet
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Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5696284 - 02/23/13 10:17 AM

Here is a great quote from Phyicist Dr. Lisa Randall that captures why those of us posting here from a scientific background do not give any credibility to Stan's "observations:"

“Although our instinct might be that observations made unaided with our eyes are the most reliable and that we should be suspicious of abstraction, science teaches us to transcend this all too human inclination. The measurements we make with the instruments we design are more trustworthy than our naked eyes, and can be improved and verified through repetition.”

Excerpt From: Randall, Lisa. “Knocking on Heaven's Door.” HarperCollins. iBooks.


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stanislas-jean
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Re: Uranus cloud bands in a C8 new [Re: telescopemullet]
      #5696327 - 02/23/13 10:44 AM

Is that personal psychology or a kind of science?
My dear, always crosscheck what is reported by different ways and make a status at final to see convergence, even for this kind of sentence given isolated and placed freely when needed for getting right only.
Sorry you get nothing more, nothing roughly in fact since the beginning here.
Stanislas-Jean


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telescopemullet
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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5696352 - 02/23/13 10:55 AM

Quote:

Is that personal psychology or a kind of science?
Stanislas-Jean




That is a quote from one of the most influential and prominent physicists practicing today. She aptly and succinctly describes with that one paragraph the essence of science. You are alone in your observations.


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stanislas-jean
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Re: Uranus cloud bands in a C8 new [Re: telescopemullet]
      #5696477 - 02/23/13 12:06 PM

Alone, are you sure?
Check the data already given and published and go to the psychanalyst.
You are on making everything as autosuggestion with your idea sorry pseudo-science of 2 peanuts.
Sorry my name is not Galileo!
Stanislas-Jean


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telescopemullet
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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5696480 - 02/23/13 12:08 PM

Yes, I am quite sure Stan.

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Re: Uranus cloud bands in a C8 new [Re: telescopemullet]
      #5696490 - 02/23/13 12:13 PM

After five months plus, you all are still arguing with someone who sees what no one else can see. Only a few can ever see what he does and those are the ones who probably saw the canals on Mars, if they had lived back then. How many of us have seen any detail in a plenatary nebula of the same size? or any other planet for that mater. With abilities like his, we should look at Mercury and contribute to our knowledge of this inner planet, but it can't be done. Yes it is possible to see some detail on Uranus occasionaly but not to see banding every time you look at the planet. If you could see this then others would see it too, but they can't. So I would say just stop arguing with him and let him do his own thing. We can argue when his work is published in a profesional journal. Until then, so what.

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Re: Uranus cloud bands in a C8 new [Re: telescopemullet]
      #5696546 - 02/23/13 12:46 PM

I am pretty sure also, because here in team.
You are alone, pretty sure also, in your head in first.
And not alone by also the data published by some other observers at the sites given, during the present opposition.
Pretty sure and probably more at the next opposition.
This is what I aimed by and through this forum.
You will not be.
Stanislas-Jean


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azure1961p
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Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5696895 - 02/23/13 04:03 PM

Stan your getting a little personal here. Mr. Mullet in quoting an important person in the field on a point of view that supports his beliefs. That's fair game Stan. In the face of it though you are making personal jabs which is unfair to others who don't want this locked up.

What you might want to consider is that no observer artist can PROVE their drawing is 100% accurate. It's a faith issue and a lot of things come together to form that. Lashing out (and granted Mr. M has been pointed too) isn't supporting your purposes. At some point you have to realize you will have some detractors. So long as you are posting in a public forum that is part of the public element.

I don't give up on Uranus personally ( though it takes gumption to bother) and Im not convinced you have seen nothing real either. It's an interesting point of interest positive or negative.

At anyrate when a person can read your blood pressure in a post - you are standing to close.

Pete


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stanislas-jean
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Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5696946 - 02/23/13 04:37 PM

Be honest with your self.
It's a matter of confidence not faith my dear and the best way to be confident is to see globally where you are on a problem.
And for knowing where you are it is necessary to synthetise the situation. And for synthetise the situation this is for the practice of analyse, practice contradictory tests, make comparison with results, compare with other observing data, etc....
What's for your famous lady is doing here? To get doubt or managing situation for refutting easily;
May I object with claiming to you for considering the views given since the beginning by me that are not autosuggestion results. Goto a lab for getting your own personal equation for viewing, it's not imagination from mind but positive action.
This is a public forum, is it not!
You have to admit the question well possible physically.
Tell me your technical argument against? Never given since the 500 posts taken place here on 2 forums. Still waiting.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: telescopemullet]
      #5697216 - 02/23/13 08:12 PM

Quote:

That is a quote from one of the most influential and prominent physicists practicing today. She aptly and succinctly describes with that one paragraph the essence of science. You are alone in your observations.




Well, I don't see any observing credentials there. Has she ever observed Uranus? Or, is this another yawn-inspiring instance of someone who can't do something, explaining why nobody else can - the "Sour Grapes" syndrome?

We have had several heavyweight observers weighing in here (directly and indirectly) on the side of seeing details on Uranus; people like David Gray, David Graham, William Sheehan, and Steve O'Meara (or haven't you read those posts?)

Perhaps Stan isn't as alone as you seem to think. Maybe the problem is in your own lack of visual acuity. To paraphrase an old quote: Just because you can't see it, doesn't mean it ain't there. Although, I doubt that you, personally, have ever tried with an open mind, and for long enough to come to any sort of intelligent conclusion.
If you're going to be a doubter, you might emulate David K., who has gone out and tried.


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Re: Uranus cloud bands in a C8 new [Re: Rick Woods]
      #5697564 - 02/23/13 11:24 PM



I get your point. I appreciate your numbers, facts and figures and percentages and I've read it all and Im not disputing the numbers .
For me though - its never happened. I'd love it too and maybe some 9/10 night it will. I can't say I've seen the planet under the best seeing I've had or the top five nights ever. So there is that. I have paltry hope though. If that 9/10 night comes when it s up and I'm out and there aren't bands Stan, you'll never hear the end of it!!!

In fun,

Pete

Edited by azure1961p (02/24/13 04:05 PM)


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telescopemullet
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Re: Uranus cloud bands in a C8 new [Re: Rick Woods]
      #5697583 - 02/23/13 11:41 PM

This is not about her observing a planet, it's about one of the world's most brilliant minds describing science. Your sour grapes comment only supports her point. I suggest you read her book.

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stanislas-jean
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Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5697783 - 02/24/13 04:58 AM

Yes my dear.
I am of the old school manners.
Now numbers quantifications are not explanations for suiting a situation for personal agreement as you imagine with your psychanalistic science.
Numbers are rather reasons why, this is quite different and a world between.
So still no argument from you.
Rather than this kind of reading, I suggest you to take information from radioastronomer who create the JT65 mode for data transmission and recently deeper modes.
You will be surprised by the fact that data are extracted from the noise without SNR ratio. How, by the singularities supported by the radio signal modulation that is quite different from the noise pattern itself. The phase modulation of the signal is the discriminator and the SNR ratio is then applying on this criteria. This is not the signal amplitude that is the lead criteria.
Now apply this to visual observations, what can be the discriminators and how you can be trained for this?
Experience is placed also in that fields and here this shall be personal.
Imagine a flight fighter pilot now at the command in hot action with rapid and fuzzy data moving at eyes, the decision oftenly has to be performed quickly without making the read of the lady book only. They are trained and experienced so experimented.
But what can cover the term of experience and qualificative experimented?
The long distanced targets views are very interresting for studying all these facts, and we know also, being lucky, that the contrast levels on planet stand still around 2%.
Where is autosuggestion?
I am HAM.
Stanislas-Jean


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Re: Uranus cloud bands in a C8 new [Re: blb]
      #5697817 - 02/24/13 05:53 AM

Quote:

After five months plus, you all are still arguing with someone who sees what no one else can see. Only a few can ever see what he does and those are the ones who probably saw the canals on Mars, if they had lived back then. How many of us have seen any detail in a plenatary nebula of the same size? or any other planet for that mater. With abilities like his, we should look at Mercury and contribute to our knowledge of this inner planet, but it can't be done. Yes it is possible to see some detail on Uranus occasionaly but not to see banding every time you look at the planet. If you could see this then others would see it too, but they can't. So I would say just stop arguing with him and let him do his own thing. We can argue when his work is published in a profesional journal. Until then, so what.




Seems to me over 11k views of this thread (10k+ on the “..Season”) might be indication of something worthwhile in spite of the often rather circular debate/s at times.

Planetary nebulae: Please point me to a one that truly matches Uranus in brightness and visual aspect. An unfortunate prefix, “planetary”, I believe coined by William Herschel, but I suspect not meant as an exact comparison. Does the Saturn Nebula really look a lot like that planet? If I were to start seeing Saturn looking like that I would reckon my observing days were over! NGC 6891 in Delphinus (a long-time favourite of mine) has been mentioned. I hope we would not use this (or any other) c.100x fainter object, with some comparatively coarser features, as a yardstick for Uranus. Perhaps I might revise my impressions if I was allowed to view it in the Palomar 5m, or suchlike, versus Uranus in my 415mm D-K, or even an 8” SCT – but very much doubt it! I have had many views through a friend’s 8” Celestron for the record – not Uranus so far!

As I said previously: next apparition I will put the 152mm off-axis stop (f/44!) on the (f/16) D-K and give it a fair (and cautious!) appraisal. Then hopefully post my impressions; if Uranus has not become CN’s Forbidden Planet by then!!


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Re: Uranus cloud bands in a C8 new [Re: David Gray]
      #5697940 - 02/24/13 09:38 AM

Not a planet but demoted to argument!

I equate these two threads as something of a tennis match. "Your Serve" might've been a better title . Still it does bear fruit.

Pete

Edited by azure1961p (02/24/13 09:39 AM)


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Re: Uranus cloud bands in a C8 new [Re: azure1961p]
      #5698070 - 02/24/13 11:03 AM

Sorry we see nothing to "confess" to you.
We are not intellectual observer, far away.
I feel your entry game of tenis play is well over, since long time.


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Re: Uranus cloud bands in a C8 new [Re: David Gray]
      #5698141 - 02/24/13 11:49 AM

Quote:

Quote:

After five months plus, you all are still arguing with someone who sees what no one else can see. Only a few can ever see what he does and those are the ones who probably saw the canals on Mars, if they had lived back then. How many of us have seen any detail in a plenatary nebula of the same size? or any other planet for that mater. With abilities like his, we should look at Mercury and contribute to our knowledge of this inner planet, but it can't be done. Yes it is possible to see some detail on Uranus occasionaly but not to see banding every time you look at the planet. If you could see this then others would see it too, but they can't. So I would say just stop arguing with him and let him do his own thing. We can argue when his work is published in a profesional journal. Until then, so what.




Seems to me