Thursday, September 8, 2016

close doubles in aquila

Clear Sky Clock predicted excellent seeing for last night, so I prepared a list of close doubles in Aquila for the night's observation.  Most were <2" separation and about half of the 25 were plotted on the CSDA, and those were the ones I observed.  Seeing is to be good tonight too, so I am printing finders for those not plotted in the atlas.  I used the 12.5-inch at 553x throughout.  I started at 9pm when seeing was good but not great, yet still had nice airy disks.  By 10pm it was very good and by 10:30pm it was fantastic, but that was when I needed to pack in.  "Wide" in my descriptions refer to the easy by which they were separated.  Some of the C pairings were missed because they weren't on the list, being wider than my cut-off criteria:

STF 2404, well split, yellow A and yellow-orange B.  [6.92, 7.77; 3.6"]

STT 368 AB: Definite split, 1/2 an airy disk width; near equal brightness.  Did not notice AC  [7.53, 8.49; 1.1"]

23 Aql AB: Pretty wide separation, just a large difference in magnitudes.  A bright orange, B bluish. [5.28, 8.29; 3.2]  Faint star much further out was the AC, 13th mag 10".

STF 2545 AB: Easy, wide separation yellow and orange.  [6.79, 8.54; 3.8"].  Did not notice C pairing.

AC 12: [Alvin Clark!]: Pretty wide separation, about 1 magnitude difference.  [7.54, 8.32; 1.5"]

52 / Pi Aql / STF 2583 AB: Very definite split.  A mini Alberio, gold and blue.  [6.34, 6.75; 1.5"]  Did not see AC pair.

STF 2596: Definite clear split, 2 airy disk widths.  (High on the ladder, hanging over to see; drive on the equatorial platform ran out!).  [7.29, 8.68; 2"]

HI 93: Easy, fairly wide separation.  [7.67, 8.39; 1.8"]

Anonymous ~ 2 minutes east of STF 2654: Bright A and faint B, ~2.5" separation.  Very nice.

65, Theta Aql: listed as having an Ab and Ac, with 1" separation, but nothing was seen.  Surely an error, or spectroscopic only -- no magnitude given for the 1" pair.

STF 2644: Nice near equal pair, wide separation.  [6.92, 7.06; 2.5"]

STF 2643: White and reddish stars, wide separation, large magnitude difference.  [8.17, 9.23; 13.8"]

STF 2651 AB: Very close but clear split, equal brightness white stars.  In a rich field.  This wasn't plotted in CDSA so I swept the area to find; I feel the thrill of discovery.  Beautiful sight.  Seeing is very calm.  Great way to end the session.  Too bad I need to go in.  [8.41, 8.44; 1.0"]

No comments:

Post a Comment