Sol Robbins
Carpal Tunnel
Reged: 12/01/03
Posts: 1540
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Hi,
I had good conditions and decided to drag out my reflector to view Venus.
Using a Wratten 47 deep violet Venus was rife with albedo features. I believe that large aperture and severe filtering is the only way to dig out these details. Wratten 38 did not really show markings nearly as well. The W47 also cleans up the seeing quite a bit.
Observing Venus is a new experience for me. It seemed that these markings were in constant flux and appeared to change with what I perceived as planet rotation, as well as, moving around the way disturbed smoke changes shape. I didn't think this was simply connected to changing seeing conditions.
As a result, I had to draw really fast in concert with these rapid positional changes, I currently don't think a reliable rendering of Venus is possible. With Venus high in the sky, I certainly am hooked on viewng it.
Sketch was done with an HB pencil with brightenings being erased out.
Best,
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Sol Robbins
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CarlosEH
Post Laureate
Reged: 01/19/05
Posts: 3115
Loc: Pembroke Pines, Broward County...
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Sol,
A truly inspirational observation of Venus. I cannot stress to other members of this forum how difficult it is to detect detail over this elusive object. I agree with you that with your aperture (9.75 inches) a Wratten 47 (Violet) filter will be useful for Venus. I have to point out that when using such a filter the seeing and transparency must be above average. Even then the detail may be fleeting, as Sol points out. Thank you for sharing this outstanding observation with us all.
Carlos
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asteroid7
Post Laureate
Reged: 10/19/04
Posts: 3716
Loc: CT
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Fine drawing catching subtle detail
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Clear Nights "Make My Day"
4.5" f/7 APM (TMB) APO Refractor on CG5 GoTo with Orion extension tube w/2" WO diagonal
5" Celestron Nexstar
8" Celestron Nexstar (8Ni)
8" Celestron CPC
Eyepieces:
40mm Pentax; 24mm Tele Vue Panoptic, 18mm Tele Vue Radian, 18mm HD Ortho, 15mm Celestron Omini,14mm Pentax,10mm Tele Vue Radian, 7mm Nagler,7.4mm Tele Vue Plossl.
2.5 Tele Vue Powermate
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kraterkid
Post Laureate
Reged: 03/07/05
Posts: 3881
Loc: Poway, California
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Stunning albeit ephemeral details Sol! Makes me wish San Diego did not have to contend with the thick marine layer that descends on us coastal dwellers every afternoon until late June (May Gray). Superb work!
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Rich 
[image]http://www.cloudynights.com/stars/CNS0606.jpg" border="0[/image]
My CN Gallery
[image]http://cleardarksky.com/c/JBObCAcs0.gif" border="0[/image]
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frank5817
Post Laureate
Reged: 06/13/06
Posts: 3041
Loc: Illinois
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Sol,
Another wonderful Venus sketch. I have a Wratten 47 violet filter in my collection. The next chance I get I am going to have a look at the Venus clouds with it. 
Frank 
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jgraham
Postmaster
Reged: 12/02/04
Posts: 5370
Loc: Dayton, Ohio
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Very nice. I've found using a blue interference filter designed for imaging works very well. Visually, the details are incredibly soft and quite beautiful. I've tried imaging using a Baader U filter with only mixed results so far.
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-John
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Homebuilt scopes from 4.25-16.5"
Meade LXD75-N6/SN6/SC8, DSX-90, ETX-60BB, ETX-125PE, DS-2130
Orion StarBlast, BinoViewers, Coronado PST
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Tasco 60mm Refractors
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Sol Robbins
Carpal Tunnel
Reged: 12/01/03
Posts: 1540
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Thanks to everyone. It really was a night of good seeing for all the planets.
Thanks again,
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Sol Robbins
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rodelaet
Carpal Tunnel
Reged: 04/28/06
Posts: 2655
Loc: 50°56' N - 4°58' E (Belgium)
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Sol,
It is a beautiful sketch with amazing details!! 
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Rony
My Astronomy Sketches
My Binocular Sketches
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Special Ed
Post Laureate
Reged: 05/18/03
Posts: 3531
Loc: Greenbrier Co., WV 38N, 80W
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Outstanding observation, Sol. I understand why you're hooked--it was the transit in 2004 that got me. I was fortunate enough to observe the aureole created by the atmosphere of Venus during egress. Now I've ordered a #47 filter because of your observations. If the 8" SCT isn't big enough to give good results, I'll try Carlos's recommendation of an 80A (light blue) filter.
Btw, Venus has the slowest rotation rate of any of the planets and rotates in retrograde motion (east to west).
Regards,
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Michael Rosolina
8" f/10 Orange Tube SCT
4.25" f/4.2 Astroscan Reflector
SVP 3.6" f/13.6 CA Reflector
40mm PST f/10
APM Germany HD 15x70 binoculars
Canon 12x36 IS II binoculars
Mark I Eyeball
My CN Gallery
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Sol Robbins
Carpal Tunnel
Reged: 12/01/03
Posts: 1540
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Rony & Michael, thanks.
Michael,
I found that the W47 worked well. I tried a deep Blue W38, which didn't seem to worked nearly as well.
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Sol Robbins
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DSalters
sage
Reged: 03/03/07
Posts: 438
Loc: High Ridge, MO (St. Louis)
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Anyone else have any thoughts regarding Michael's comment? It's the first thing I thought of when reading Sol's initial post. Venus' ridiculously slow rotational period would keep the clouds there in pretty constant formation. I think noticing constant changes would have to be from actually seeing these clouds in their (relatively steady) positions BUT fighting with seeing conditions here on earth at the same time.
Any thoughts?
-Daniel
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6" f/8 Bushnell Voyager Dob. Rebuild
10" f/5 Highe Dob. variant
(UNDER CONSTRUCTION: 5" f/5, 8" f/6, 13" f/4.6)
Baader Hyperions--Primary Eyepieces
"The sun has one kind of splendor, the moon another and the stars another; and star differs from star in splendor." -1 Corinthians 15:41
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Jay_Bird
professor emeritus
Reged: 01/04/06
Posts: 680
Loc: Nevada 36N 115W
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I wondered the same thing. As Special_Ed noted, Venus is the roational slowpoke to Jupiter's speed demon, and it seems even with 100's of MPH winds, changes in the clouds of Venus would occur over hours, not minutes. Seeing could make such details much more fleeting, as Carlos said. Certainly a 'pushing the envelope' observation, much fine detail seen and recorded from a challenging subject.
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Sol Robbins
Carpal Tunnel
Reged: 12/01/03
Posts: 1540
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I looked at my sketch and th rotational arrow is facing the wrong way.
Albedo details also moved left to right rather quickly.
These details never returned back to its former positions.
Limb brightenings rapidly changed size and shape.
I hope to observe Venus again under good to very good seeing conditions.
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Sol Robbins
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DSalters
sage
Reged: 03/03/07
Posts: 438
Loc: High Ridge, MO (St. Louis)
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I by no means meant to sound critical and hope you did not feel that way. I was just bringing up a point about Venus' rotation and thought maybe that would help anyone curious about its features. The detail you bring out in your sketches is amazing. I look forward to your next Venus sketch. They help us all see what can be seen with the 47 filter and a careful eye.
-Daniel
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6" f/8 Bushnell Voyager Dob. Rebuild
10" f/5 Highe Dob. variant
(UNDER CONSTRUCTION: 5" f/5, 8" f/6, 13" f/4.6)
Baader Hyperions--Primary Eyepieces
"The sun has one kind of splendor, the moon another and the stars another; and star differs from star in splendor." -1 Corinthians 15:41
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Sol Robbins
Carpal Tunnel
Reged: 12/01/03
Posts: 1540
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Daniel,
I don't take what you said negatively in any kind of way. I also hope you didn't think I was being defensive. I honestly appreciate folks for being critical. I guess it might have been the way I wrote my response. I apologize.
I was amiss in that I don't know what I really saw, scientifically speaking, other than what appeared to me observing through my scope. I hope others will seek details, of any kind, when observing Venus. This current apparition has a relatively high elevation at twilight.
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Sol Robbins
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DSalters
sage
Reged: 03/03/07
Posts: 438
Loc: High Ridge, MO (St. Louis)
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Sol,
I certainly did not think you were being defensive. I just got to thinking maybe I worded things poorly and felt bad, so I said what I did. No need to apologize; everything's all right
You are very correct about this apparition being so high. I always try for details on Venus but never go into it with an open enough mind, I suppose. My 80A filter is not going to help enough either. Perhaps I should invest in a 47 considering it's probably my only hope for seeing any cloud details.
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6" f/8 Bushnell Voyager Dob. Rebuild
10" f/5 Highe Dob. variant
(UNDER CONSTRUCTION: 5" f/5, 8" f/6, 13" f/4.6)
Baader Hyperions--Primary Eyepieces
"The sun has one kind of splendor, the moon another and the stars another; and star differs from star in splendor." -1 Corinthians 15:41
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Special Ed
Post Laureate
Reged: 05/18/03
Posts: 3531
Loc: Greenbrier Co., WV 38N, 80W
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Hello all,
I went on a mini-marathon of observing since we had 3 clear days in a row with solar, planetary, cometary, and DSO observations so I'm a little backed up getting things posted. I made this observation of Venus Tuesday evening (9 May UT) during late twilight.
I don't have the #47 filter yet so I used the #80A. Seeing was decent (V was still high) so I was able to discern some albedo in the Venusian cloudtops. The duskiness was more pronounced near the limb and lightened towards the center of the disk. The limb arc was very bright, even in the filtered view.
I used a template downloaded off the Venus Section of ALPO and modified somewhat. Btw, the template had preceding and following mislabeled--I wonder if they know that? I used a stump loaded with graphite and an eraser.
As Sol mentioned, Venus will be high in the sky all month--this is a really good opportunity to study it and learn more about how to observe it.
Here's my impression of Venus. Thanks to Sol for leading the way on this--he sets the standard for Venus sketches.
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Michael Rosolina
8" f/10 Orange Tube SCT
4.25" f/4.2 Astroscan Reflector
SVP 3.6" f/13.6 CA Reflector
40mm PST f/10
APM Germany HD 15x70 binoculars
Canon 12x36 IS II binoculars
Mark I Eyeball
My CN Gallery
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Sol Robbins
Carpal Tunnel
Reged: 12/01/03
Posts: 1540
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Michael,
Great sketch.
I don't wish to start a Venusian mutual admiration society, but I have to admit I am a bit excited about the prospect of trading Venus observations.
I don't remember Venus being so high up in the sky as it is now. Additionally scope cool down is a cinch and we don't have to freeze in order to catch a good view. Don't even need a flashlight to draw by either.
I also recommend sending a copy of this to ALPO's Venus coordinator as Venus images are always a bit small in number compared to the other planets. I think there is also a downloadable page of observing tips as well.
Thanks again,
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Sol Robbins
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Achernar
Post Laureate
Reged: 02/25/06
Posts: 3720
Loc: Alabama, USA
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I have a deep violet filter also, but I've never seen this sort of details on Venus. Usually the seeing's just too poor, and these cloud features so faint I usually just see the phase of the planet and how the atmosphere scatters the sunlight around the disk near inferior conjunction. There are substances whose identity remains unknown in the clouds that cause these faint markings, which are whipped around the planet at 200 plus mph because the atmosphere "super-rotates" around the bulk of the planet. This is a nice drawing which echos images taken of Venus at ultraviolet wavelengths from spacecraft.
Taras
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10-inch F/4.5 Discovery Dob
6-inch F/8 Homebuilt Dob
4 1/4-inch F/4 Homebuilt reflector
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CarlosEH
Post Laureate
Reged: 01/19/05
Posts: 3115
Loc: Pembroke Pines, Broward County...
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Michael,
An excellent observation of Venus showing some albedo features over it's disk. I am glad to see that this detail was visible to you using the Wratten 80A (light blue) filter. I hope to be able to observe Venus and the other planets soon. I look forward to your (and Sol's) future observations.
Carlos
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