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Astraforce Paul
Carpal Tunnel
Reged: 04/05/05
Posts: 1879
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Was out observing M15 last night... nice globular, bright core. It was positioned in the middle of the stem of a Y or T-shape set of 4 fairly bright stars.
I mention this because I was mistakenly looking at Pennington's description of M5 where he mentions a nearby double star (5 Serpentis). I had noticed that one of the 4 bright surrounding stars looked astigmatic and when I put higher power on it, I saw a nice tight double, with some subtle color differences.
I didn't discover until this morning that I had been on the wrong page, and reading the description of the wrong globular cluster! [Hey, go easy on me! I assume that similar mistakes have happened to most all observers!  ]
Today, though, in looking at various planetarium programs, I've been unable to find the double! Of course, if I had thought even a bit, I would have remembered just how bright and distinctive 5 Serpentis is and caught my mistake.
So, any ideas of what I saw?
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Just occurred to me that I probably should have put this post in the Double Star section! Oh, well, another error!
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walt r
Post Laureate
Reged: 02/13/07
Posts: 3463
Loc: Doylestown, PA
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What was the FOV?
How far away from the center of M15 was the double?
I did find in the Washington catalog in Cartes du Ciel STF2799 at Mags7.37/7.44, sep=1.8", but its 1° from M15 to the SSW.
Yep, understand the wrong page thing. Easy to do in the dark.
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Walt
Obsession 18" f/4.45 #1370 AN/SC
MK67 Deluxe 6" f/12 Mak-Cass, Super Polaris GEM, JMI MicroMax DSC
DIY 60mm f/6 Achromat
Cookbook 245 CCD
Edited by walt r (08/26/09 10:56 AM)
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Astraforce Paul
Carpal Tunnel
Reged: 04/05/05
Posts: 1879
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Let's see, with M15 in the center, it was nearby, maybe 1/5, maybe 1/3 of the eyepiece fov which was about 1.5 degrees. So, maybe .3-.5 of a degree.
Hmm... that's a very rough memory estimate. When I check in Voyager, the likely candidates are maybe 17' away. HR 2831? HIP 106075 or HIP 106243? But those aren't double stars.
They separated cleanly in a 9mm, at 50x, so the separation had to be say 10".
We've had cloudy weather or I'd check it again in real life!
Edited by Astraforce Paul (08/28/09 06:04 PM)
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JakeSaloranta
sage
Reged: 09/18/08
Posts: 236
Loc: Sisu, Sauna, Sibelius...
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Why don't you just generate an Palomar Observatory Sky Survey-image 60' x 60' in size around M15. The missing double should be visible in the prints if it is close enough to Messier 15.
http://stdatu.stsci.edu/cgi-bin/dss_form
/Jake
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BillFerris
Carpal Tunnel
Reged: 07/17/04
Posts: 2910
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My sketch from an old observation of M15 shows a close pairing of stars about 15' southeast of the globular. These are not cataloged as a double. In MegaStar, one is ID'd as GSC 1127:0370, a star simmering in the vicinity of 11th magnitude. Its partner appeared equally bright during my observation. This pair is separated by 20" to 30". Perhaps, this is the pair you saw.
Bill in Flag
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Grand Canyon Adventure
Lowering the Threshold
18" Obsession
4.5" Meade 4500
10x50 Swift Audubon
Cosmic Voyage
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