31 august 2021

I set up both scopes last night, the 6-inch to view Calisto's shadow transit, and the 20-inch for some doubles.  Unfortunately the seeing was poor so I was masked to 7-inches throughout.  The Calisto transit was nice: I could see the elongated shadow and on the opposite limb of Jupiter I could see the moon itself.  Its gibbous phase helped give a dark contrast to Jupiter's disk and to soften the appearance of the moon itself so the moon's disk could be seen.  It struck me that the best time to try to see detail on the Galilean moons is during their transits, with Jupiter helping to provide the bright contrast backdrop.  Will try again later this Jupiter season with the 20-inch, if seeing and sky cooperate.

STF2385 AB: 178; 205x: White A and can see B first with averted vision and then can hold with direct, 3 delta mag, wide.  Not physical per WDS, but this is incorrect!  4% parallax range overlap but only 55 parsecs; 300 AU weighted separation, and 1.08/0.64 stellar mass; and the radial velocity delta (1.07) is less than the escape velocity (3.18), so it is gravitationally bound!
18h 46m 33.09s +16° 58' 59.5" P.A. 30.00 sep 5.5 mag 8.42,10.80 Sp G0

WFC 216 AB: 178; 205x: Slightly unequal white stars, framed with two 10th mag stars on either side, equidistant away.  WDS uncertain, but they do not share any parallax range overlap.
18h 55m 04.26s +16° 44' 20.3" P.A. 89.00 sep 12.0 mag 9.07,9.55 Sp A2

COG 1 AB: 178; 205x: Unremarkable, wide, 1.5 delta magnitude white stars, maybe in a triple as a third star a little farther out forms a triangle (this is AC).  Not physical per WDS, and no data on the companion in Gaia.  W.A. Cogshall, assistant to T.J.J. See at the Lowell Observatory, but by 1903 he was observing with the 12-inch at the Kirkwood observatory where this discovery was made, following a list made by Burnham of stars suspected to be double by the Albany observers.  
18h 55m 43.67s +12° 54' 30.1" P.A. 284.00 sep 26.2 mag 9.28,11.92 Sp A5V dist. 763.36 pc (2490.08 l.y.)

STF2485 AB: 178; 205x: White A, B seen with averted vision only, well separated.  WDS uncertain, but there is 75% parallax range overlap, 1,872 AU weighted separation, and 2.07/1.07 solar mass -- likely to be gravitationally bound.
19h 14m 12.81s +23° 08' 21.7" P.A. 320.00 sep 8.5 mag 8.54,11.40 Sp F2

STF3132 AB: 178; 205x: 2 delta B seen with averted vision only.  There are two other faint stars, WAL 113 AC and AD.  Forms a double-double with STF2530 in the same field.  WDS says physical, and there is 21% parallax overlap, 1,441 AU weighted separation, and 1.40/1.06 solar mass.  However the radial velocity delta (2.07) exceeds the escape velocity (1.74), so likely will not remain gravitationally bound.

19h 28m 12.76s +20° 12' 59.6" P.A. 39.00 sep 8.0 mag 10.10,11.80 Sp G5

STF2530 AB: 178;205x: 1.5 delta mag, about 4" separation, white stars.  In same field with STF2132.  WDS uncertain, but there is 77% parallax range overlap, 577 AU weighted separation, solar mass 1.17/0.92, and the radial velocity delta is less than the escape velocity, so they are very likely gravitationally bound.
19h 28m 22.08s +20° 19' 08.2" P.A. 155.00 sep 5.6 mag 9.44,10.70 Sp G0

ARY 19 AB: 178; 205x: Super-wide near equal.  Why thought of as double?  COU1028Aa-Ab is 0.3" 9.30/10.0, a good target for the 20-inch, and BD is COU1029, 7.4" 9.38/13.00.  AB not physical per WDS, 
19h 33m 18.55s +26° 28' 41.1" P.A. 13.00 sep 48.5 mag 8.86,9.38 Sp F2

STF2540 AB: 178; 205x: Pretty light yellow A and 2 delta reddish B, very nice.  WDS uncertain, but they do not share parallax ranges.
19h 33m 17.05s +20° 24' 50.5" P.A. 147.00 sep 5.4 mag 7.52,9.23 Sp A3 dist. 152.67 pc (498.01 l.y.)

STF2560 AB: 178; 205x: White A, B just barely seen with direct vision as a very small point, >3 delta mag, wide.  WDS says not physical, and they do not share parallax ranges.
19h 40m 39.58s +23° 43' 04.7" P.A. 299.00 sep 14.2 mag 6.64,10.51 Sp B6IV dist. 510.2 pc (1664.27 l.y.)