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stanislas-jean
Carpal Tunnel


Reged: 10/22/08

Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5468278 - 10/13/12 12:49 PM Attachment (59 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
Carpal Tunnel


Reged: 10/22/08

Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5484832 - 10/23/12 07:18 AM Attachment (37 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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Eddgie
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Reged: 02/01/06

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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stanislas-jean
Carpal Tunnel


Reged: 10/22/08

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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stanislas-jean
Carpal Tunnel


Reged: 10/22/08

Re: Uranus cloud bands in a C8 new [Re: stanislas-jean]
      #5486983 - 10/24/12 01:05 PM Attachment (34 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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Eddgie
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Reged: 02/01/06

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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stanislas-jean
Carpal Tunnel


Reged: 10/22/08

Re: Uranus cloud bands in a C8 new [Re: Eddgie]
      #5487988 - 10/25/12 01:39 AM Attachment (36 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 1.6Ám.
In a certain way a comparison basis, but at 0.619Ám 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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azure1961p
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Reged: 01/17/09

Loc: USA
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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stanislas-jean
Carpal Tunnel


Reged: 10/22/08

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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Eddgie
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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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stanislas-jean
Carpal Tunnel


Reged: 10/22/08

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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stanislas-jean
Carpal Tunnel


Reged: 10/22/08

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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Asbytec
Guy in a furry hat
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Reged: 08/08/07

Loc: La Union, PI
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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telescopemullet
professor emeritus
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Reged: 11/16/09

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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stanislas-jean
Carpal Tunnel


Reged: 10/22/08

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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Cotts
Just Wondering
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Reged: 10/10/05

Loc: Toronto, Ontario
Re: Uranus cloud bands in a C8 [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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azure1961p
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Reged: 01/17/09

Loc: USA
Re: Uranus cloud bands in a C8 [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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stanislas-jean
Carpal Tunnel


Reged: 10/22/08

Re: Uranus cloud bands in a C8 [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, 1.6Ám, 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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azure1961p
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Reged: 01/17/09

Loc: USA
Re: Uranus cloud bands in a C8 [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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Asbytec
Guy in a furry hat
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Reged: 08/08/07

Loc: La Union, PI
Re: Uranus cloud bands in a C8 [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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