16 december 2022, binaries

Observed with the 20-inch in fairly good seeing. I logged around 17- objects, all from the known-binary list, but the laptop I use and which has the logs died, so I don't have many to report except for the short periods where I wrote the observations down in my notebook. The rest will have to wait for a new laptop to arrive and the software recovery.

HU 304 AB: 508; 850x: Suspected not single at lower powers, the equal white stars was a clean split at 850x on up through 1270x, with apodizing mask. I could not tell which star was brighter, but the position angle was following a NE-SW line. It gave me less trouble than I expexted since brighter pairs throw off a lot of diffraction. Pretty cool that this pair, discovered in 1901 at 0.3" and with a 54.7-year period, has made a little more than two complete revolutions to be resolved visually again.  WDS grade 2 orbit, no reason to doubt it, and anyway there's no Gaia parallax data available.
04h 23m 51.84s +09° 27' 39.5" P.A. 38.30 sep 0.31" mag 5.80,5.90 Sp A0V+A1V dist. 121.36 pc (395.88 l.y.)

BU1007 AB: 508; 1270x: Snowman, 1 Dm, very tough, broken up with diffraction, PA to the south.  Actual PA more WSW, and a WDS grade 2 orbit 111.02-year period.  No Gaia data for the secondary.  This will become undetectible until the late 2050s.  Burnham writes: "Discovered with the 12-inch on Mt. Hamilton in 1881.  It was single or too close for the 36-inch 1890-92.  The measures since then show but little change in the angle, but a while revolution may be covered by the observations.  The components are nearly equal, and therefore some of the measures may require a correction 180 degrees.  In my measure with the 40-inch in 1897 it was noted: 'The distance is less than 0.3"; the smaller star is p.'  In the first set of measures in 1881 with the 12-inch it was stated: 'The measured distances are decidely too large.'  The distance is probably always less than 0.25".  There is little double of its being a binary of short period."  

05h 41m 17.72s +16° 32' 03.1" P.A. 255.90 sep 0.124" mag 5.04,6.56 Sp B8V+B7V dist. 194.93 pc (635.86 l.y.)

STT 79 AB: 508; 570x: Very pretty light orange primary, grey-blue B, 1 Dm, nice close split, PA to north.  WDS grade 2 orbit, 89.7-year period, no Gaia data for the secondary.  This will widen slightly and be more firmly to the northeast by 2040.

04h 19m 54.78s +16° 31' 21.6" P.A. 15.80 sep 0.679" mag 7.26,8.62 Sp F9V dist. 46.53 pc (151.78 l.y.)

I made an attempt at A3010, and thought I had an elongation with north-south PA, but it is really to the east and I obviously did not have it. Discovered in 1901 at 0.1", it has an extrodinary fast 1.19-year period with a grade 3 orbit. The nice thing is this will be at apistron just next year, so I can certainly give it another go.