Sunday, September 12, 2021

10 september 2021

Still feeling tired from the trip to Fremont Peak, I spent an hour and a half with the 6-inch, through good transparency and average seeing.  I could not push magnification too high, but there were still many worthwhile pairs to look at.  A perfect scope for such a night.

I spent most of the time in Cepheus, since it's a bit out of reach or within roof currents for the 20-inch.

STF 2806 AB: 152; 175x: Alfirk.  Bright yellow-green and 3 delta mag, bluish b, wide.  WDS uncertain, no Gaia data on the primary.
21h 28m 39.58s +70° 33' 38.5" P.A. 251.00 sep 13.5 mag 3.17,8.63 Sp B1IV dist. 210.08 pc (685.28 l.y.)

STF 2893 AB: 152; 175x: Light orange A and light blue 3 delta mag., very wide.  A feels like it's a snowman (no other companion to A).  WDS says physical, which is unusual for a wide separation, but it does share 23% parallax range overlap, 6,332 AU weighted separation but pretty high solar mass 3.74/2.03.
22h 12m 52.76s +73° 18' 25.9" P.A. 348.00 sep 28.9 mag 6.19,7.91 Sp G8III dist. 210.97 pc (688.18 l.y.)

BU 1092 AB AB: 152; 245x: AB is a near equal snowman to 245x, power limited by average seeing.  Wide 1 delta star, which is STTA AB-D, 7.56/8.42 42.2".  Physical with a 48.93-year period, currently at apastron and will close rapidly by 2040.  Burnham discovered with the 36-inch at 0.3" and later noted "The very recent measures of AB by Aitken with the 36-inch (power 1900) show decided change in angle and distance.  It is probably in rapid motion." 
22h 36m 08.65s +72° 52' 51.1" P.A. 222.50 sep 0.4 mag 8.30,8.30 Sp F5 dist. 84.46 pc (275.51 l.y.)

STF 2965 DE: 152; 175x: Finest 1 delta mag stars, fairly close.  WDS says physical, and this is likely correct: 99% parallax range overlap, 716 AU weighted separation, 2.18/1.80 solar mass. 
22h 55m 46.65s +72° 50' 35.6" P.A. 220.00 sep 2.9 mag 8.42,9.38 Sp A0 dist. 248.14 pc (809.43 l.y.)

STT 489 AB: 152, 380x: Pi Cep.  Round star image only, though I have feelings of brightening in the diffraction, but it does not resolve.  Physical with 556-year period.  
23h 07m 53.84s +75° 23' 15.3" P.A. 4.00 sep 1.1 mag 4.61,6.80 Sp G0IV dist. 75.64 pc (246.74 l.y.)
STF 2963 AB: 152; 245x: Noticeably unequal pair, faint and very close, about 1".  WDS is uncertain, however they probably are gravitational: 45% parallax range overlap, 256 AU weighted separation, 1.78/1.61 solar mass.
22h 54m 15.01s +76° 20' 17.4" P.A. 2.00 sep 1.9 mag 7.95,8.53 Sp A3 dist. 123 pc (401.23 l.y.)

STF 3017 AB: 245; 175x: Very faint 1 delta mag, split with seeing only.  WDS uncertain, but a strong case they are gravitational: 63% parallax overlap, 149 AU weighted separation, 1.78/1.48 solar mass.
23h 27m 42.90s +74° 07' 09.5" P.A. 19.00 sep 1.2 mag 7.64,8.51 Sp F1:V dist. 105.93 pc (345.54 l.y.)

STF 2984 AB: Light orange 2 delta mag stars, close, real nice!  WDS uncertain, but it likely is gravitational: 3% parallax range overlap, 1,193 AU weighted separation, 3.01/1.67 solar mass, and the radial velocity delta (1.68) is less than the escape velocity (2.63).  
23h 07m 22.27s +70° 39' 39.5" P.A. 295.00 sep 4.8 mag 7.63,9.82 Sp G8III dist. 293.26 pc (956.61 l.y.)

STF 3001 AB: Bright orange A seems out of round [this is AB].  2 delta mag bluish C, well separated.  Physical with a 2198-year period, B is slowly coming off periastron.  88% parallax range overlap, 204 AU weighted separation, 2.60/1.46 solar mass 
23h 18m 37.41s +68° 06' 41.1" P.A. 223.40 sep 3.4 mag 4.97,7.28 Sp G8III dist. 62.27 pc (203.12 l.y.)

STF 2948 AB: 152; 175x: Lovely ice-blue A, 1 delta mag B, close about 3".  WDS uncertain, however the parallax ranges do not overlap.  
22h 49m 36.21s +66° 33' 13.8" P.A. 3.00 sep 2.6 mag 7.26,8.60 Sp B6Vn dist. 261.78 pc (853.93 l.y.)

STTA 238 AB: 152; 175x: Wide, white, slight delta mag.  WDS says physical, however I don't find data on the secondary -- it is very close to us at only 192 light years, so maybe the very wide angular separation is less of an issue.
22h 52m 42.28s +67° 59' 24.5" P.A. 280.00 sep 69.2 mag 7.02,7.58 Sp F2 dist. 59 pc (192.46 l.y.)

STF 2923 AB: 152; 175x: Classic Struve.  White stars, fairly wide, 2 delta mag.  WDS says physical, however their parallax ranges do not overlap.
22h 33m 16.76s +70° 22' 25.3" P.A. 47.00 sep 9.6 mag 6.32,9.24 Sp A0V dist. 125.79 pc (410.33 l.y.)

STF 2883 AB: 152; 175x: Yellow-white A and 2 delta B, wide.  Spectral class F2V (yellow-white).  WDS says physical, and there is 93% parallax range overlap, 477 AU weighted separation, 1.58/0.79 solar mass, and the radial velocity delta (0.25) is less than the escape velocity (2.97), so they are very likely gravitational.
22h 10m 38.79s +70° 07' 57.2" P.A. 253.00 sep 14.2 mag 5.56,8.56 Sp F2V dist. 33.59 pc (109.57 l.y.)

ARY 45 AB: 152; 175x: Finder split with STF 2883 in the field, equal white, very wide.  WDS says physical based on shared proper motions, however they do not have any parallax range overlap (-27%), so they are not gravitational.
22h 08m 17.22s +69° 58' 56.4" P.A. 207.00 sep 66.7 mag 7.86,8.11 Sp B9.5V dist. 240.38 pc (784.12 l.y.)

STF 2903 AB; 152; 175x: Light yellow A, <1 delta mag B, fairly wide.  WDS uncertain, and they do not share their parallax overlap, -21%.  STT 470 in the same field, a double-double.
22h 21m 45.20s +66° 42' 22.6" P.A. 97.00 sep 4.1 mag 7.13,7.80 Sp A7V+G0III dist. 268.82 pc (876.89 l.y.)

STT 470 AB: 152; 175x: Double-double with STF 2903.  White stars, 3 delta mag, fairly close.  WDS uncertain, but they probably are gravitational: 8% parallax range overlap, 492 AU weighted separation, 1.91/1.02 solar mass.
22h 20m 57.68s +66° 57' 54.5" P.A. 351.00 sep 4.3 mag 7.37,9.77 Sp A7V dist. 104.82 pc (341.92 l.y.)

HDS3216 Aa-Ab: 152; 245x: Nice! very fine, 2 delta mag, just separated.  I was going for STT 475 but this is 16" separated, I'm surprised I got this closer pair.  Unfortunately they do not share the same parallax overalp.
22h 39m 04.59s +37° 22' 31.6" P.A. 50.00 sep 0.6 mag 6.83,10.52 Sp B2:V+SB dist. 5555.56 pc (18122.24 l.y.)

STF 2843 AB: 152; 245x: Very faint, near equal, just split.  Nice!  WDS uncertain, but very likely gravitational: 70% parallax range overlap, 122 AU weighted separation, 1.78/1.68 solar mass.
21h 51m 37.25s +65° 45' 09.9" P.A. 150.00 sep 1.4 mag 7.01,7.28 Sp A1m dist. 87.57 pc (285.65 l.y.)

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