Saturday, July 10, 2021

9 july 2021

Back out again last night, though the seeing was noticeably worse and there was a thicker haze.  We even had smoke blowing in from a fire somewhere in the area, but that cleared up at around 10pm.  I spent most of the time with the 7-inch mask on but did re-observe the STF2339 double-double, which was my goal for the night.

STF1959 AB: 178; 205x: Close and faint at this scale, B is 1 delta mag, white stars.  WDS uncertain, however there is no overlap in the parallax range, so not gravitationally bound.
15h 34m 44.13s +34° 43' 22.8" P.A. 244.00 sep 2.2 mag 9.79,10.81 Sp F8

COU 801 AB: 178; 205x: Faint and a bit difficult with the small aperture and low magnification, mostly elongated but does resolve and split with seeing.  This one is likely to be gravitationally bound, there is 45% overlap in the parallax range and 399 AU separation.
15h 48m 43.01s +32° 39' 36.4" P.A. 196.00 sep 1.5 mag 11.32,11.83

RS CrB: John Herschel's red stars.  A very dull weak orange

STF2023 AB: 178; 205x: Nice well split, almost 2 delta mag, light yellow stars.  Spectral class F5, yellow-white.  18% parallax overlap and 216 AU separation, this is likely gravitationally bound.
16h 14m 30.89s +05° 31' 21.0" P.A. 222.00 sep 1.8 mag 8.70,9.38 Sp F5

STF2027 AB: 178; 205x:  Tight but good split, near equal light yellow stars.  Spectral class F0, yellow-white.  22% parallax overlap, 373 AU separation, likely to be gravitationally bound.
16h 15m 16.64s +04° 15' 46.6" P.A. 81.00 sep 1.9 mag 8.77,8.86 Sp F0 dist. 271 pc (884 l.y.)

STF2026 AB: 178; 205x: Wide, <1 delta mag white stars.  433.7911-year period it is approaching apastron.  The AC pair is LEP 78 AC, sep 581.7 mag 9.48,17.49, discovered in 2000, which claims to be physical, however Gaia data shows there is no overlap in the parallax ranges and even the proper motions are divergent.
16h 15m 57.07s +07° 21' 24.8" P.A. 16.10 sep 3.6 mag 9.48,9.86 Sp K5 dist. 26.04 pc (84.94 l.y.)
 

KU 52 AB: 178; 205x: The b star is averted vision only, wide, 1 delta mag.  16% parallax overlap, 4,934 AU separation, with 2.18 solar mass, so likely to be gravitationally bound. 
16h 19m 44.39s +10° 54' 00.9" P.A. 50.00 sep 9.5 mag 10.14,11.50 Sp F0

STF2097 AB: 178; 205x: Fine slight delta pair, well split.  No parallax overlap.
16h 44m 47.22s +35° 44' 16.7" P.A. 79.00 sep 1.9 mag 9.37,9.55 Sp G5 dist. 125 pc (407.75 l.y.)

STF2101 AB: 178; 205x: Nice 2 delta wide pair, white A star and blue B.  4% parallax overlap and 243 AU separation, however the escape velocity exceeds the radial velocity delta, so it will not remain gravitationally bound.
16h 45m 48.14s +35° 37' 50.5" P.A. 48.00 sep 4.1 mag 7.51,9.39 Sp F6V dist. 58.82 pc (191.87 l.y.)

STF2104 AB: 178; 205x: Ice blue-white A and light red B, 2 delta, wide.  WDS uncertain but there is 67% parallax overlap and 1,114 AU separation, with the primary 2.45 and secondary 1.73 solar mass -- very likely to be gravitationally bound.
16h 48m 41.48s +35° 55' 19.3" P.A. 18.00 sep 5.7 mag 7.49,8.78 Sp F2 dist. 172.71 pc (563.38 l.y.)

BU 1250 AB: 178; 205x: Can see it steadily split at small scale at 205x, bluish stars at one corner of a triable of near equal magnitude stars.  I get a wider split but needing more averted vision at 445x.  Discovered with his 6-inch, Burnham notes: "It is the s star of a small equilateral triangle, all in the field."  No parallax overlap, not physical.
17h 24m 49.67s +30° 44' 24.0" P.A. 121.20 sep 1.9 mag 10.83,11.13

STF2165 AB: 178; 205x: Wide nearly 2 delta, blue-white A and slightly red B.  Not physical.
17h 26m 13.76s +29° 27' 20.4" P.A. 62.00 sep 10.4 mag 7.74,9.55 Sp Am dist. 231.48 pc (755.09 l.y.)

COU 498 AB: 508; 445x: Barest of hairline splits with seeing, near equal white stars.  WDS uncertain, and no Gaia data for either star.
17h 27m 36.36s +26° 23' 56.8" P.A. 40.00 sep 0.5 mag 10.35,10.32 Sp F2

HU 322 AB: 508; 889x: Very subtle notched elongation, PA on an E-W line but a little cocked from WAK 21.  Component of STF 2339 AB-CD.
18h 33m 45.62s +17° 43' 55.9" P.A. 92.50 sep 0.2 mag 7.74,8.91 Sp F6V dist. 183.49 pc (598.54 l.y.)

WAK 21 CD: 508; 889x: Clean split, near equal bluish color stars, PA E-W.  Component of STF 2339 AB-CD.  No Gaia data so can't determine if gravitationally bound.
18h 33m 45.62s +17° 43' 55.9" P.A. 263.00 sep 0.5 mag 9.30,9.56 Sp F6V dist. 183.49 pc (598.54 l.y.)

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