4 september 2022

It's been very hot these last few days, which typically promises good seeing -- as was the case last night.  But usually there is so much radiative cooling from all the buidings and roads etc. it takes quite a while for it to really settle down.  I could not stay up that long, so I went after a few challenge objects before settling on some more Struves.  Ended the night with Saturn, which looks pretty good now at opposition.

A 1377 AB: 508; 1334x: Notched elongation, very close to splitting but it would not.  A is a deeper orange than lighter yellow-orange B, PA to south/southeast, 1 Dm.  The STF2348 AB-C pair is a bright struve, easy and wide.  WDS grade 3 orbit, 205.9-year period, it will widen slightly and be more due south by 2050.  No Gaia data for the companion.
18h 33m 56.69s +52° 21' 12.6" P.A. 137.70 sep 0.2 mag 6.20,6.40 Sp G9III dist. 195.69 pc (638.34 l.y.)

HU757 BC: 508; 1067x: STF2450 A-BC is 3 Dm, well split, bright light orange A, blue BC which in poor seeing is just an elongated smudge, but with seeing it resolves to two stars, PA to the east, significant delta, very close but split.  WDS grade 4 orbit for BC, 116-year period, it will widen slightly and turn northeast by 2050.  No Gaia data for C.

19h 02m 06.53s +52° 15' 42.3" P.A. 93.00 sep 0.2 mag 10.30,10.40 Sp G8III: dist. 214.13 pc (698.49 l.y.)

A 1391 AB: 508; 900x: Very fine hairline split, 1 Dm, pretty tough in hazy skies.  WDS grade 3 orbit, 138-year period, it will widen slightly and reach further to the northeast by 2050.  No Gaia data on the companion.
19h 10m 36.61s +54° 28' 35.1" P.A. 32.20 sep 0.3 mag 9.17,10.05 Sp F8 dist. 179.21 pc (584.58 l.y.)

STF2513 AB: 178; 145x: White stars, well separated, >1 Dm.  WDS uncertain, but there is no overlap of the parallax ranges, -94%, it is not binary.

19h 25m 11.29s +02° 27' 27.5" P.A. 330.00 sep 2.0 mag 8.57,9.47 Sp F8 dist. 87.41 pc (285.13 l.y.)

STF2519 AB: 178; 145x: Wide, half delta magnitude, white stars.  WDS says parallax indicates physical, and there is 14% parallax range overlap, 1,388 AU weighted separation, 1.6+1.5 Msol, so there is some chance it is binary.
19h 28m 12.93s -09° 32' 15.9" P.A. 124.00 sep 12.0 mag 8.34,8.54 Sp F1 dist. 90.74 pc (295.99 l.y.)

STF2541 AB: 178; 145x: 2 Dm, well split.  WDS says physical, but there is no overlap of the parallax ranges, -47%, it is not binary.
19h 36m 45.65s -10° 26' 36.6" P.A. 327.00 sep 5.4 mag 8.72,10.09 Sp K2V dist. 27.89 pc (90.98 l.y.)

STF2545 AB: 178; 145x: White stars, nearly 3 Dm, wide.  WDS uncertain, yet there is 69% overlap of the parallax ranges, only 336 AU weighted separation, 1.9+1.2 Msol, so chances are good it is binary, someone should run an orbit.
19h 38m 43.36s -10° 09' 23.7" P.A. 326.00 sep 3.7 mag 6.79,8.54 Sp A9III dist. 86.28 pc (281.45 l.y.)

STF2543 AB: 178; 145x: Light yellow A, wide 3 Dm B.  WDS uncertain, but there is no overlap of the parallax ranges, -94%, it is not binary.
19h 36m 12.61s +06° 00' 26.7" P.A. 151.00 sep 11.5 mag 6.76,10.45 Sp G8III dist. 201.61 pc (657.65 l.y.)

STF2544 AB: 178; 300x: Very close hairline split more than one delta magnitude, very tough.  WDS uncertain, but there is no overlap of the parallax ranges, -5%, it is not likely binary.
19h 37m 06.23s +08° 18' 52.0" P.A. 183.00 sep 1.0 mag 8.62,9.88 Sp A3

STF2582 AB: 178; 300x: Nice close split with 145x, well split at 300x, 2 Dm, light orange stars.  WDS uncertain, but there is no overlap of the parallax ranges, -5%, it is not likely binary.

19h 49m 49.27s -03° 55' 20.6" P.A. 258.00 sep 2.5 mag 8.67,9.93 Sp G5 dist. 377.36 pc (1230.95 l.y.)

STF2589 AB: 178; 145x: Near equal white stars, wide.  WDS uncertain, but there is no overlap, -20%, of the parallax ranges, it is not binary.

19h 52m 32.57s +00° 38' 56.3" P.A. 294.00 sep 4.9 mag 8.58,8.87 Sp A0 dist. 139.08 pc (453.68 l.y.)

STF2597 AB: 178; 445x: Excellent pair, snowman nearly 2 Dm at 300x, hairline split at 445x.  WDS grade 4 orbit, 425-year period, with little change by 2050.  No Gaia data for the companion.
19h 55m 19.49s -06° 44' 04.7" P.A. 99.40 sep 0.8 mag 6.94,7.98 Sp F2V dist. 81.83 pc (266.93 l.y.)

STF2627 AB: 179; 300x: Very faint, 2 Dm, B is barely detected, very closely split.  WDS says physical, but there is no overlap of the parallax ranges, -26%, sadly it is not binary

20h 07m 42.53s +04° 46' 28.6" P.A. 32.00 sep 2.0 mag 9.67,10.81 Sp A5

STF2643 AB: 178; 145x: White A and dull orange, well split B.  WDS uncertain, and there is no overlap, -15%, of the parallax ranges, it is not binary.
20h 12m 47.31s -02° 59' 45.4" P.A. 81.00 sep 3.0 mag 7.09,9.40 Sp A0V dist. 133.33 pc (434.92 l.y.)

STF2636 AB: 178; 145x: Wide 1 Dm.  WDS says proper motion indicates physical, but there is no overlap of the parallax ranges, -47%, it is not binary.
20h 11m 39.98s -04° 35' 24.4" P.A. 203.00 sep 12.5 mag 9.41,10.36 Sp B9V+B6V dist. 671.14 pc (2189.26 l.y.)

STF2654 AB: 178; 145x: White, wide, near equal.  WDS says parallax indicates it's physical, and there is 57% overlap of the parallax ranges, 1,299 AU weighted separation, 1.9+1.5 Msol, and the radial velocity delta 1.1 is less than the escape velocity 2.1, is it likely binary and needs an orbit run.
20h 15m 10.63s -03° 30' 12.9" P.A. 233.00 sep 14.4 mag 6.96,8.14 Sp F2V+F4V dist. 41.43 pc (135.14 l.y.)

STF2678 AB: 178; 145x: White stars, equal, well split.  WDS says proper motion indicates physical, and there is 35% overlap of the parallax ranges, only 332 AU weighted separation, 1.0+1.0 Msol, so it is likely binary.
20h 25m 50.00s -08° 18' 09.7" P.A. 310.00 sep 3.4 mag 9.85,10.22 Sp G5

STF2656 AB: 178; 145x: White A, B is quite faint but seen directly, wide.  WDS uncertain, but there is no overlap of the parallax ranges, -10%, it is not binary.
20h 15m 37.14s +07° 48' 32.4" P.A. 233.00 sep 9.7 mag 7.34,11.30 Sp A7III dist. 122.7 pc (400.25 l.y.)

STF2635 AB: 178; 145x: Yellow-white A and faint wide B.  WDS says proper motion indicates physical, but there is no overlap, -16%, of the parallax ranges, it is not binary.

20h 10m 07.83s +08° 26' 37.8" P.A. 80.00 sep 7.7 mag 6.66,10.19 Sp F7V dist. 62.74 pc (204.66 l.y.)