Posted 07 May 2011 - 07:35 AM
Attached are two drawings I made of Saturn on 5th May. The winds finally died down and the seeing was unusually good at times. i was able to use powers of x250 and x312 to make some reasonable drawings. I also was able to make intensity estimates in IL, W80A and W11. My impressions of the globe and rings were as follows:
Globe: SPR rather dark a STB and SEB seemed to be present. The STropZ and EZ(s)(?) were also bright. The EZ(n) contained a yellowish EB, a lovely light egg shell colour was present in the zone. NEB was a double feature with NEB(n) being the most well defined of the two components and rather dark. The storm was near the proc limb and rather bright, it seems to me to be in the lower (northern) part of the NTropZ and cuts into the NTB and possibly the NTZ. Also of interest was a veil structure connecting the NTB with the NEB(n), spanning the NTropZ. The NTropZ and NTZ were rather bright (the NTZ in a more uniform manner) and I was under the impression that the NTB contained darker (and thicker?) sections. NNTB seemed uniform and a the NPR were dark and dusky.
Rings: A-Ring darker at it's outer edge and still a light brown colour. Cassini Division still fairly easy to see. The B-Ring was of interest. The B1-Ring appeared to be brighter than the last time I looked at it, and was a white-light grey colour. The B2-Ring seemed irregular in places- at the ansae centre it seemed as though the B1-Ring cut into it (as shown in drawing 1). I am reasonably confident that there were darker sections present in the B2-Ring (spokes?) as shown in drawings 1 and 2. C-Ring seen, best observed at ansae centre.
2315UT: #80A(Blue) Tethys looked distinctly brighter in this filter compared to IL.
2317UT: #47 (Violet). No disk deatils are discernable in this light but it is clear that the B1 Ring is the brightest feature on Saturn.
2323UT: #25A (Red). The belts come out well in this light, and I was impressed enough to make a drawing with this filter (drawing 2). I think the spokes in the rings may come out better in this light too, but the seeing has dropped of a little so i cannot be certain.
By 2334UT some kind soul had let it slip to Spode that I was having a good night and a single cloud parked itself over Saturn the rest of the sky was (naturally) clear. However by 2339UT, clouds came in proper and I had no choice but to retire for the night.
Link to image
Posted 07 May 2011 - 06:49 PM
Very nice subtle detail in the rings and on the planet's clouds. The spokes(?) in the B ring and brightening in the C-ring near the ansae positions are beautifully rendered.
Posted 07 May 2011 - 08:46 PM
Very fine and detailed observation report and sketches. The storm appeared bright to me, too. I like that spoke detail you're seeing in the rings but it must take pretty good seeing.
I don't even get mad anymore when the only cloud in the sky is right in front of what I want to look at--I just sigh in a resigned manner...
Posted 08 May 2011 - 10:01 AM
Excellent observations of Saturn in integrated light (IL) and red light (Wratten 25). I surmise that the storms over the North Temperate Belt (NTB) must extend deep into the Saturnian atmosphere as they are prominent in red light (W25). Thank you for sharing them with us all. I look forward to your future observations.