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spokes

Started by kcolter, 09/13/2002 02:07PM
Posted 09/13/2002 02:07PM Opening Post
No, I can't say I have seen spokes in Saturn's rings. I have been seeing something in these stellar seeing conditions we have been having. What I see is primarily at the ansae and looks sometimes like the crepe ring has bled up on the B ring. Missouri has had an almost unprecedented run of clear steady early mornings that has seen me out 15 of the last 17 mornings for the 2 or 3 hours before dawn. On the best days I have been able to use 405X on Saturn with 7 inches of aperture without losing image quality. I wish I had been using larger aperture on some of these mornings.
I have seen the Voyager pictures of spokes. I would be interested in hearing from those who have seen them about what they saw, how they compared to the voyager pics, what aperture and magnification was needed to see them, etc. I know Kevin Barker has seen them and I am sure others have as well. Keep the stable air coming. In these early am hours I have been splitting 0.8 and 0.9 arc second doubles nicely. I need to find some .5 to .7 doubles that are well placed at that hour. Suggestions?
Kim Colter
Posted 09/13/2002 02:24PM #1
Kim,

If you look for close double stars, I suggest 7 Taurii a couple of degrees east of the Pleiades. The present separation is about 0"7. In the evening you may try Eta Coronae Borealis and Beta Delphini. Both are 0"6 or slightly below. Beta Delphini is most difficult to split cleanly doe to its brightness.

One problem with sub-arcsec doubles is that their real separation also is small in most cases. Many of them are late main sequence or dwarf stars, and relatively close to the solar system. As a result of the small separation, the orbital period is low, and therefore they change separation and position angle quite rapidly. This makes double star interesting, but it is very difficult to find a relatively fixed pair below 1".
Posted 09/14/2002 12:00AM #2
Kim
You seem to be having excellent time of viewing saturn etc with the steady air. I have just checked my log book and see that it was November 1998 that I saw the markings on Saturn's rings. I was using only 100 mm of aperture.
It was not discernible with a C8(too much brightness per contrast??)Although on the same night a suspected division in the A ring was apparent in the C8.

It was not all that hard to make out when seeing was still. It appeared on one side and looked like a V that started from the C/B ring boundary. I saw it three or four times around 14th Nov 1998. I called them Tores at the time. The crepe ring was also plainly visible on both Ansae.

I have not seen the feature since but will put the 130 into action tomorrow morning to take a peek if the weather settles a little.

Have you sketched your observations??

best wishes

Kevin B

The rings were not as open back in 1998 so maybe the brightness makes these features more difficult to see??
Posted 09/14/2002 06:07AM #3
Kim - I'm quite envious at your seeing that level of detail in the rings! Which instrument?


Clear Skies!

Jim (Mahon)