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Uranus cloud bands in a C8

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#176 stanislas-jean

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Posted 05 January 2013 - 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.asahik...13/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
 

#177 stanislas-jean

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Posted 11 January 2013 - 03:14 PM

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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#178 stanislas-jean

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Posted 17 January 2013 - 01:56 PM

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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#179 DHurst

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Posted 18 January 2013 - 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! ;)
 

#180 stanislas-jean

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Posted 18 January 2013 - 12:51 PM

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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#181 stanislas-jean

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Posted 27 January 2013 - 05:00 AM

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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#182 telescopemullet

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Posted 29 January 2013 - 06:13 PM

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

#183 starrancher

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Posted 29 January 2013 - 07:18 PM

Geez Mullet :lol: :lol: :lol: let it go . :roflmao:
 

#184 Gil V

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Posted 29 January 2013 - 08:04 PM

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

#185 azure1961p

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Posted 29 January 2013 - 09:39 PM

You want WHAT????


Pete
 

#186 stanislas-jean

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Posted 30 January 2013 - 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
 

#187 mark8888

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Posted 30 January 2013 - 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.
 

#188 stanislas-jean

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Posted 30 January 2013 - 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
 

#189 telescopemullet

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Posted 31 January 2013 - 01:18 PM

Geez Mullet :lol: :lol: :lol: let it go . :roflmao:


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.
 

#190 azure1961p

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Posted 31 January 2013 - 08:03 PM

.
 

#191 Rick Woods

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Posted 01 February 2013 - 12:29 AM

Geez Mullet :lol: :lol: :lol: let it go . :roflmao:


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?
 

#192 David Knisely

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Posted 01 February 2013 - 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.
 

#193 azure1961p

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Posted 01 February 2013 - 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...
 

#194 David Gray

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Posted 01 February 2013 - 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!!
 

#195 David Gray

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Posted 01 February 2013 - 10:22 AM

As said previous post The (f16)D-K has a 19% central obstruction - see here:
http://alpo-j.asahik...12/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.
 

#196 Rick Woods

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Posted 01 February 2013 - 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.
 

#197 telescopemullet

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Posted 01 February 2013 - 12:00 PM

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.
 

#198 Rick Woods

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Posted 01 February 2013 - 12:43 PM

What a wit.
 

#199 t.r.

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Posted 01 February 2013 - 12:49 PM

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.
 

#200 David Gray

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Posted 01 February 2013 - 01:23 PM

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.asahik...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.asahik...11/u110121z.htm
and, abandoning the computer drawing idea, here:
http://alpo-j.asahik...12/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!

Attached Files


 






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