10 july 2024, movement pairs

For once the actual seeing met the forecast.  We're under a high pressure heat dome, and it provided for some very steady air, even from my sea level back yard.  I used the 20-inch and observed until 2:00am.  I had some pointing accuracy problems, and the serial cable between my laptop and the ServoCAT got tangled in my ladder (I need to get around to installing the WiFi connection) -- but altogether it was a very fine night.  I wore a t-shirt until midnight, and then only a long-sleeved shirt, it was so warm.  Airy disks held up at 600x, and there was only moderate diffraction breakdown at higher magnifications.  

STF1937 AB: 508; 635x: Using blue filter to suppress the bright stars' diffraction, and apodising mask, wonderful close split, uneven pair, PA north.  SOC grade 1 orbit, 41.63-year period, it will reach apastron just shy of 1" in 2030. 

15h 23m 12.23s +30° 17' 17.7" P.A. 287.00 sep 0.609" mag 5.64,5.95 Sp F8V+G0V dist. 17.86 pc (58.26 l.y.)

JEF1 AB: 508; 1270x: Nusakan, 3 CrB.  With apodising mask and blue filter, I can detect the position angle of the elongation as SSE.  Currently 0.15", it will widen quickly in the next couple of years reaching apastron in 2028 at 0.314".  SOC grade 1 orbit, 10.54-years period.

15h 27m 49.85s +29° 06' 19.8" P.A. 140.00 sep 0.3 mag 3.68,5.20 Sp A5+F2 dist. 34.28 pc (111.82 l.y.)

BU  648 AB: 508; 420x: Pretty light yellow-orange A and 2 Dm, more richly orange B, good split, PA SW.  SOC grade 2 orbit, 63.25-year period, it will tighten over the next decade but should still be detectible in 2036 at 0.6".  No Gaia parallax data for B.

18h 57m 01.61s +32° 54' 04.6" P.A. 232.00 sep 1.2 mag 5.34,7.96 Sp G0V dist. 14.87 pc (48.51 l.y.)

HU 1176 AB: 508; 1700x: Single to very slightly out of round all powers, apodising mask and blue filter, but can't tell PA. SOC grade 1 orbit, only an 8.14-year period!  It will reach apastron ~3/31/2027 at ~0.13".  I don't expect to split it then, but I might be able to identify the position angle.

17h 08m 02.08s +35° 56' 06.8" P.A. 114.00 sep 0.1 mag 6.10,6.10 Sp A5m dist. 54.26 pc (177 l.y.)

STT 327 AB: 508; 850x: Very slightly unequal pair, good clean split, PA to north.  SOC grade 2 orbit, 88.4-year period, it will tighten over the next couple of decades, reaching periastron in the late 2050s.

17h 14m 06.83s +56° 08' 01.7" P.A. 334.00 sep 0.4 mag 8.29,8.95 Sp F2 dist. 86.36 pc (281.71 l.y.)

HU 1179 AB: 508; 1270x: From 420x - 850x I see overlapping light orange disks.  Split with 1270x, unequal stars, PA to the west.  Great pair.   SOC grade 2 orbit, currently 0.252", it will tighten over the next 20 years to <0.15".

17h 24m 02.26s +38° 34' 57.7" P.A. 272.00 sep 0.252" mag 7.13,7.79 Sp F9III dist. 175.44 pc (572.29 l.y.)

STF2173 AB: 508; 1270x: Very strongly notched elongation / overlapping disks, PA is on a N-S line but I can't tell which is B, the stars are equal.  Some atmospheric dispersion playing with the star colors (one blue, the other orange).  SOC grade 1 orbit 46.4-year period, it is currently 0.264" separated and will widen considerably over the next decade, reaching 1" apastron around 2038.  No Gaia data for the secondary.

17h 30m 23.78s -01° 03' 46.2" P.A. 104.00 sep 0.264" mag 6.06,6.17 Sp G5V dist. 16.34 pc (53.3 l.y.)

BU  151 AB: 508; 1270x: Using an apodising screen and blue filter, from 500-850x I had strongly notched elongation, and was able to cleanly split the pair at 1016x and 1270x for seconds at a time when seeing stilled.  The closeness makes the difference in magnitude appear greater than it is (it appeared 2 Dm vs the 1 Dm it really is).  SOC grade 1 orbit, currently 0.375", it will widen to apastron in 2030 0.588".  My field sketch is off on the PA, I placed it too far north.

20h 37m 32.87s +14° 35' 42.7" P.A. 218.00 sep 0.375" mag 4.11,5.02 Sp F5IV+F2V dist. 30.93 pc (100.89 l.y.)

KUI  99 AB: 508; 500x: Excellent light orange stars, well split airy disks in excellent seeing, 2 Dm, PA to SE.  SOC grade 2 orbit, 38.7-year period, currently 0.644" it will reach apastron in 2029 at 0.911, then dive back to apastron by 2040.

20h 39m 37.71s +04° 58' 19.3" P.A. 111.00 sep 0.644" mag 8.28,9.63 Sp K5V dist. 16.72 pc (54.54 l.y.)

WCK 2 Aa-Ab: 508; 1270-1700x: Component of BU 298, very weak olive shape with PA to the SW at best moments, with apodising mask and blue filter.  SOC grade 2 orbit, 17-year period, it is currently 0.207 and remain at that separation but turn due south by July 2029 before closing very quickly through the 2030s, not to be detectible (by me) again until the 17-year period is completed. 

20h 39m 38.25s +15° 54' 43.4" P.A. 289.00 sep 0.1 mag 3.86,6.43 Sp B9IV dist. 77.82 pc (253.85 l.y.)