Uranus cloud bands in a C8
Posted 09 November 2012 - 01:44 AM
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.
Posted 09 November 2012 - 03:29 AM
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.
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.
Posted 09 November 2012 - 04:41 AM
Posted 09 November 2012 - 06:52 AM
Since 2009, Stan the Uranus Man has posted his drawings here: http://alpo-j.asahik...est/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.
Posted 09 November 2012 - 07:53 AM
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.
Posted 09 November 2012 - 08:13 AM
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.
Posted 09 November 2012 - 01:05 PM
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!
Posted 09 November 2012 - 01:37 PM
Posted 09 November 2012 - 04:35 PM
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.
Posted 09 November 2012 - 05:30 PM
Posted 10 November 2012 - 02:12 AM
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.
Posted 10 November 2012 - 04:18 AM
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.
Posted 15 November 2012 - 04:44 PM
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.
Posted 23 November 2012 - 02:59 AM
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
Posted 23 November 2012 - 05:02 AM
Posted 23 November 2012 - 08:03 AM
But there is the worst and the best that are issue on the forum.
Posted 02 December 2012 - 05:13 AM
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).
Posted 03 December 2012 - 12:34 PM
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.
Posted 10 December 2012 - 01:58 AM
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.
Posted 12 December 2012 - 02:20 PM
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.
Posted 13 December 2012 - 01:41 AM
We will see later.
Posted 17 December 2012 - 05:05 PM
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.
Posted 31 December 2012 - 11:45 AM
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,
Posted 02 January 2013 - 03:25 AM
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.