doubles and the moon

I had a nice session last night with the 12.5-inch, observed for two hours and had a fun, relaxing night.

I started out with Saturn at 277x with the apodizing screen.  Seeing was not quite settled but there were some good steady moments.  Aside from the usual Cassini Division and cloud band colors, I was struck by color darkness variations in the D / C rings, especially near the inner arcs.  It could be due to the angle of the rings I was seeing through more material and that part of the ring appeared darker as a result?

Next I viewed some double stars, choosing to view as straight up as I could, just past meridian, in Hercules.  The wide base of my orchard ladder meant that even though I set it close the to dobsonian base platform, my eye was too far away from the finder scope and eyepiece, and I needed to lean uncomfortably far over the side to see.  I think I will need to rotate the tube to put the eyepiece out lower down.  Seeing was good, Pickering 7.  Of course I was lazy and didn't try to measure these pairs, it was more just enjoying the thrill of seeing a double in the eyepiece.  My findings on Stelle Doppie are bracketed.  Mostly at 277x:

STT 328: Very bright A & much fainter B, fairly widely separated.  [4.5" sep, A 4.7 mag, B 10.3]

STF 2181: Might be a triple?  Brighter yellow-red A and two stars, both rather faint, about the same separation but 120 degrees apart in PA.  [Triple confirmed; A is 7.04 mag, B 10.54, C 12.55; sep 32.6" & 38.6" 110 degree difference in separation]

STT 157: Yellow A, widely separated from blue B.  2 magnitude difference.  If placed on edge of field can see bright orange star.  [In fact a multiple system, A has two close 0.8" separated faint stars which I didn't see.  The AB pair is as described.]

STF 2220: Very bright yellow-white A, wide separation from fainter B.  [This is in fact a complex multiple system with stars separated by 0.1, 0.6, 36, 321, and 335".  STF 2220 proper is a A, BC triple.  Pretty remarkable but no chance for me to detect the richness of the system.]

Anonymous, forms a triangle with STF 2220 & 87 Her, approximately 17h 45m +27 deg.: Faint red A and very faint B, also red.  A real delight to see this, the nice surprise and wonder of a double star.

Anon, to SW, approximately 17h 40m +26 degrees: Bright A and wide 3x fainter B.  Why anonymous in the CDSA?  It should be easy in a smaller telescope.

STF 2194 was a pretty orange and blue pair, 3 magnitude difference, nicely separated [What I saw was the AB pair, 16.3" separation 6.51 vs 9.28 magnitude.  The AC pair is 170.6" sep and a similar magnitude]

STF 2232 is a nice white and blue pair, widely separated and 2 magnitudes difference.  [Agrees well, 6.3" separation and 6.71 vs 8.85 mag]

STF 2280 is a near equal bright white pair, clearly separated [I saw the AB pair, 14.4" separation & 5.81 & 5.84 magnitude.  The AC pair is 79.9" separation and 11.80 for the C.]

Es 471: (discovered by Rev. T. E. H. Espin, who according to The Binary Stars by Aitkin "in 1901 began publishing lists of new double stars discovered with his seventeen and one-fourth inch reflector.  The first list contained pairs casually discovered in the course of other work; later, Mr. Espin undertook the systematic observation of all the stars in the Bonn Durchmusterung north of +30 degrees, recording, and, as far as possible measuring, all pairs under 10" not already known as double.  At this writing [1918] his discoveries have reached the total of 1,356."  What I wrote in my notes was an uncertain observation: Very close white or faint wide separation B, bluish.  I seem to have observed the AC pair which matches my second description with 7.21 A mag and 10.20 B mag.  But this is in fact another complex multiple system: Espin found the AB and AC pair, the B and C having nearly the same separation but the B 14.20 magnitude, and spinning around the A at different PAs.  There are earlier observations of three more stars, the C, D, & E, which all share a barycenter with A.  These were discovered by Guy Soulie (SLE), a French astronomer who published lists between 1966-2007.  Now, doesn't such a storied and interesting object deserve a more careful look than I gave it?

h1303: Fairly bright A, wide separation to a faint B.  [6.22 mag A, 11.75 B, 39.8 sep]

STT 338:  !! Nice!  Used 553x.  Just split, a pair of bright orange stars.  Is there a third with wide separation? [Actually a quadruple system.  I observed the AB pair, 0.8" separation 7.21 & 7.38 -- so the seeing was quite good.  I probably saw the AC pair, 13.1 mag and 32.6" separation.  The AD pair is 11.6 mag and 96.3" separation.  This was the double of the night!]

STF 2215, Bright white A and very faint wide B.  [This is a miss.  Actual separation is 0.5" and they have similar magnitudes]

STF 2245: Very pretty orange and blue.  Alberio like, but fainter and closer together; and the stars are about equal magnitude.  [2.7" sep 7.43 A, 7.55 B]

STF 2190: Bright yellow A and fainter  blue B.  Wide separation.  All by itself in Hercules' leg.  [AB 10.4" 6.13 / 9.48.  AC discovered by WAL (Wallenquist) 76.4" sep, 12.71 sep]

STF 2160: Bright white A, fainter and reddish B, wide separation.  [3.7", not so wide; 6.4 and 9.28 mag]

STF 2140 = Rasalgethi, Bright orange A & pale green much fainter B.  Very nice!

By this time the nearly full moon had cleared the "meridian tree," as I am calling it: a large tall pine tree in our neighbor's yard which is just to the east of meridian from where the 12.5-inch telescope is mounted.  I can guestimate meridian passage for any object using the tree.  I wanted to use low power on the moon (71x 1.1 degree TFOV), to just take it all in.  Low power moon with larger aperture is just stunning.  So many features, and the enormity of some of the craters and their ejecta trails become clear.  I gazed for a good half hour before it was time to go to bed.  I could have looked at it all night.