27 september 2024, movement pairs

Observed with my 20-inch.  Good transparency and better than expected seeing, so I went after pairs on my "movement" list, with very good results.  Once it cleared the meridian tree I had a nice view of Saturn.  All with apodising screen.

 A 1238 AB: 508; 1270x: Very difficult, need moments of best seeing, unequal pair, barely split, PE to the NE.  SOC grade 2 orbit, and unfortunately it will remain a very difficult pair through its turn N to W through 2040.

23h 08m 47.77s +10° 57' 31.1" P.A. 70.00 sep 0.2 mag 8.20,8.79 Sp F6V dist. 119.19 pc (388.8 l.y.)

AGC  13 AB: 508; 400x: Using an apodising screen and a blue filter, the secondary was clear and steady in light diffraction, nicely separated from the primary, PA SSE, best seen at 400x.  I also put on a 7-inch off-axis mask (effective f/14.3), still at 400x and with the blue filter.  The star image was greatly cleaned-up, with one faint diffraction ring.  B was dimmer but I could still hold it easily.  SOC grade 2 orbit, 49.52-year period, it will be due east by 2034 and a very difficult 0.5".

21h 14m 47.49s +38° 02' 43.1" P.A. 190.00 sep 1.1 mag 3.83,6.57 Sp F3V+F7V dist. 20.34 pc (66.35 l.y.)

BU 1212 AB: 508; 1270x: Unequal, PA SSW, light yellow, hairline at best moments.  SOC grade 2 orbit, 48.65-year period, it will gradually widen to the west and be an easy 0.5" by 2042.  Burnham says in his GC: "Discovered with the 36-inch.  It was evident at the time of discovery [1890.75, 0.45" 254.5-degrees or WSW] the close pair was a binary from the common proper motion of the components, as otherwise the duplicity would have been seen long ago [I suspect it was too close for most observers to see or measure, such as STT]....The motion of AB is slow so far, but it is probable that the components have about the maximum separation at this time, and that hereafter the angular motion will be more rapid [he was essentially correct on this point!].

21h 39m 31.39s -00° 03' 04.1" P.A. 156.00 sep 0.1 mag 6.94,8.44 Sp F6V dist. 43.98 pc (143.46 l.y.)

KUI 108 AB: 508; 1270x: Light orange stars, out of round only, unequal PA to N.  SkyTools says the period is 26.5-years, and SOC offers this orbital solution, showing the pair at apastron now.

21h 42m 22.94s +41° 04' 37.3" P.A. 14.00 sep 0.2 mag 6.33,6.72 Sp A0V dist. 126.42 pc (412.38 l.y.)

KUI 114 AB: 508; 1270x: Light orange star, out of round or olive shaped, PA SE.  SOC grade 2 orbit, which is nearly edge-on, 54.57-year period, the pair will soon dive back to periastron soon, emerging and detectable on the opposite PA in the mid-2040s.

22h 40m 47.97s -03° 33' 15.4" P.A. 129.00 sep 0.35 mag 6.52,8.63 Sp F6V dist. 34.57 pc (112.77 l.y.)

STT 535 AB: 508; 1270x: Using an apodising mask and blue filter, at >500x the elongation was obvious, and bumping the magnification up to 1270x I had a clean split, slightly unequal stars with PA to the NE.  Spurious disks were fairly steady but there was a fair amount of dancing diffraction at this magnification.  I observed it in October 2020 with the 20-inch, when it was at 0.165", and it appeared single.  So this makes a handful of pairs in which I've been able to trace movement over the last few years.  We have another four years or so before the secondary makes its dive back toward the primary and will be undetectable visually.  What a fun observation, 5.71-year period!  SOC grade 1 orbit.

21h 14m 28.81s +10° 00' 25.1" P.A. 7.00 sep 0.33" mag 5.19,5.52 Sp F6V+F6V dist. 18.49 pc (60.31 l.y.)