2 october 2024

Another good night on the 20-inch.  I started at 9:30pm after another hot day.  Worked the CDSA list for a while.  Seeing was predicted to be excellent after 11pm, but it didn't improve much -- but I was still pleased with the session, there were still many fine and challenging pairs to observe.

BAR 12 Ba-Bb: 508; 850x: Seeing not cooperating. Notched elongation, PA N-S line but I can't tell which is which. No Gaia data for the secondary.  SOC grade 4 orbit, 400-year period.

20h 20m 46.55s -14° 47' 05.5" P.A. 52.00 sep 0.4 mag 6.16,9.14 Sp A0III dist. 104.06 pc (339.44 l.y.)

BU 74 AB: 508; 420x: Excellent!  Very fine bluish B, nearly 2 Dm, very closely split.  Seen intermittently with lower magnification.  No Gaia parallax data for the secondary.

21h 35m 11.99s +21° 24' 14.9" P.A. 338.00 sep 1.0 mag 7.45,9.05 Sp F5V dist. 85.18 pc (277.86 l.y.)

BU 148 AB: 508; 500x: Light orange unequal stars, split, PA to the south.  No Gaia data.  SOC grade 5 orbit, 783-year period, if correct it will tighten for the next 40 years.

19h 52m 01.89s -10° 21' 13.5" P.A. 219.00 sep 0.6 mag 7.74,8.41 Sp F2 dist. 86.96 pc (283.66 l.y.)

BU 164 AB: 508; 1270x: Appears single, at periastron, splitable by 2040.  Burnham discovered at 0.64" with the 6-inch, and he predicted the period would be slow.  No Gaia data for the secondary.  SOC grade 4 orbit, 361-year period.

21h 25m 05.66s +09° 23' 02.6" P.A. 93.00 sep 0.1 mag 8.17,8.30 Sp A5IV-V dist. 136.05 pc (443.8 l.y.)

BU 681 AB: 508; 500x: Wow!  Extremely fine, light orange A pretty bright, B is just beyond A's first diffraction and very faint, a tiny white dot with seeing.  -47% PRO, it is not binary.

21h 13m 16.58s +16° 55' 08.4" P.A. 242.00 sep 2.9 mag 7.48,10.92 Sp K3III dist. 213.68 pc (697.02 l.y.)

COU 430 AB: 508; 635x: With seeing, PA to SW, very faint B well separated at this magnification.  No Gaia data for the secondary.

21h 25m 09.48s +18° 27' 45.4" P.A. 229.00 sep 0.8 mag 7.95,9.41 Sp A0 dist. 177.3 pc (578.35 l.y.)

HO 292 AB: 508; 195x: Faint B held with foveal coaxing, well split. -57% PRO, it is not binary.

22h 23m 15.11s +05° 38' 47.8" P.A. 64.00 sep 4.4 mag 7.66,11.24 Sp A2 dist. 141.04 pc (460.07 l.y.)

STF2658 AB: 178; 140x: White A and light orange B, well separated, 2 Dm.  89% PRO, 251 AU WS, 1.3+0.8 Msol, it is likely binary.  SOC grade 5 orbit, 5631-year period.

20h 13m 40.74s +53° 07' 30.3" P.A. 106.00 sep 5.2 mag 7.19,9.38 Sp F5V dist. 44.33 pc (144.6 l.y.)

STF2729 AB: 508; 635x: Split at 420x, best seen at 635x, light orange stars about 1 Dm, clean split.  No Gaia data on the secondary.  SOC grade 2 orbit, 200-year period.  This is actually a Herschel discovery, in 1783.  Not a true Struve.

20h 51m 25.69s -05° 37' 35.9" P.A. 35.00 sep 0.7 mag 6.40,7.43 Sp F5IV-V dist. 60.72 pc (198.07 l.y.)

STF2786 AB: 178; 140x: White stars, well split, slightly unequal.  -27% PRO, it is not binary.

21h 19m 39.36s +09° 31' 30.3" P.A. 188.00 sep 2.8 mag 7.49,8.20 Sp A3IV dist. 185.53 pc (605.2 l.y.)

STF2797 AB: 178; 140x: Easy, well separated, > 1 Dm.  38% PRO, 624 AU WS, 2.4+1.7 Msol, and RVD 1.3 < EV 3.4, it is likely binary and needs an orbit tried.

21h 26m 41.14s +13° 41' 17.8" P.A. 218.00 sep 3.5 mag 7.37,8.83 Sp A2V dist. 221.73 pc (723.28 l.y.)

STF2799 AB: 178; 140x: Equal white stars, closely split.  -27% PRO, it is not binary.

21h 28m 52.79s +11° 05' 05.2" P.A. 259.00 sep 1.9 mag 7.37,7.44 Sp F4V dist. 105.04 pc (342.64 l.y.)

STF2809 AB: 178; 140x: 2 Dm very wide.  19% PRO, 3,508 AU WS, 2.4+1.2 Msol, but RVD 2.7 > EV 1.4, it is not binary.

21h 37m 33.76s -00° 23' 26.0" P.A. 163.00 sep 31.1 mag 6.22,9.36 Sp A2III+F5V dist. 112.87 pc (368.18 l.y.)

STF2854 AB: 178; 200x: Near equal dull white, close split.  45% PRO, 130 AU WS, 1.4+1.4 Msol, it is likely binary and needs an orbit.

22h 04m 22.52s +13° 38' 53.4" P.A. 84.00 sep 1.6 mag 7.77,7.89 Sp F6V dist. 72.1 pc (235.19 l.y.)

STF2878 AB: 178; 200x: Lovely close split, 2 Dm.  -53% PRO, it is not binary.

22h 14m 29.18s +07° 58' 34.2" P.A. 116.00 sep 1.6 mag 6.94,8.11 Sp B9IV dist. 224.22 pc (731.41 l.y.)

STFA 56 AB: 178; 140x: Super-wide, nearly 2 Dm.  -83% PRO, it is not binary.

21h 37m 43.64s +06° 37' 06.2" P.A. 349.00 sep 38.7 mag 6.18,7.50 Sp A2V dist. 145.35 pc (474.13 l.y.)

STFB 11 AB: 178; 140x: Bright white A and wide 2 Dm B. -82% PRO, it is not binary.

21h 22m 05.13s +19° 48' 15.7" P.A. 313.00 sep 36.6 mag 4.20,9.30 Sp K1III+K0V dist. 47.78 pc (155.86 l.y.)

STTA222 AB: 178; 140x: 1 Dm, super-wide.  51% PRO, 8,370 AU WS, 1.7+1.4 Msol, but RVD 0.9 > EV 0.8, and the fact the weighted separation is >5,000 AU, it is not likely binary.

21h 44m 07.92s +07° 09' 29.7" P.A. 258.00 sep 87.4 mag 7.49,8.47 Sp F2V