7 april 2022 early morning observing

Yesterday the Clear Sky Chart forecast was for solid dark blue boxes, which meant 100% clear skies, excellent transparency, excellent seeing -- but only starting at 1am 4/7 to dawn.  Since conditions like that don't come very often, I decided to observe during those wee hours.  I took a short nap in the afternoon, opened the shed during the late afternoon to start cool-down, and took another short nap in the late evening.  I started observing around midnight.  The first quarter moon had not quite set, but the light haze around it told the tale: the lower elevations of the Bay Area was still under a bubble of marine haze, which wrecked the transparency and would hurt the seeing too.  I decided to continue.  I found I could still use full 20-inch aperture, but the seeing and transparency would fuzz the stars out if I tried to go over 600x.  I tried to keep to higher elevations, though the seeing did improve enough at 2am for me to go into Virgo, since I had nearly tapped out my short period and physical lists higher up.  Still a very worth-while session, many very fine pairs observed.  I lasted until 3:30am when I finally packed in and slept on the couch until the rest of the family got up at 6am to start their day.

BU 604 AC: 508; 150x: Bright white A, very faint C seen direct vision in the glow A casts off in poor transparency, very wide separation.  Burnham discovered with the 18.5-inch.  15.7 mag AB not seen.   WDS says not physical, and I can't find the Gaia data for the pair.
11h 49m 03.58s +14° 34' 19.4" P.A. 25.00 sep 101.2 mag 2.14,13.20 Sp A3V dist. 11 pc (35.88 l.y.)

A 2375 AB: 508; 600x: Clean, well split light orange stars, <1 Dm, PA to the south. WDS gives a 152.5-year period, nearing apastron and won't change much the next 20 years.  Grade 3 orbit.  There is -20% parallax range overlap, meaning none, and only 46 AU weighted separation and 1.0+1.0 Msol.  It may eventually be found this is not truly a binary.
10h 58m 28.33s +17° 11' 06.2" P.A. 165.00 sep 0.5 mag 10.44,10.03 Sp G5 dist. 109.77 pc (358.07 l.y.)

HEI 360 AB: 508; 150x: Pretty, near equal white stars, well split around 4".  WDS uncertain, but there is 26% parallax range overlap, 579 AU weighted separation, 1.1+1.0 Msol, and the radial velocity delta 0.0 is less than the escape velocity 2.5, so it is more than likely to be binary.
10h 59m 30.13s +12° 48' 05.5" P.A. 102.00 sep 3.8 mag 9.90,10.00 Sp G5

A 1773 AB: 508; 200x: Very nice white and 2 Dm close B, 2 Dm, PA NE, which was revealed while increasing magnification from 150x.  WDS uncertain, but there is 33% parallax range overlap, 335 AU weighted separation, 1.4+1.0 Msol, so it is likely to be binary.
11h 03m 19.03s +23° 22' 36.5" P.A. 43.00 sep 2.4 mag 9.31,11.50 Sp G0

HO 48 AB: 508; 300x: Excellent pair, seen with 200x but better at 300x, white stars, 2 Dm B, nice and closely separated around 2".  WDS uncertain, but there is 78% parallax range overlap (though with 9% error), 366 AU weighted separation, 1.9+1.1 Msol, so it is likely to be binary.
11h 03m 57.05s +23° 08' 51.3" P.A. 355.00 sep 1.8 mag 8.61,10.79 Sp G0 dist. 255.75 pc (834.26 l.y.)

STF1506 A-BC: 508; 150x: Typical Struve, light yellow A and wide blue B, 2 Dm.  A676 BC is a component, I have hints of NS elongation at 600x but this might be atmopsheric dispersion.  WDS says A-BC proper motion indicates physical, however there is no Gaia data for the B star(s).

11h 04m 41.47s -04° 13' 15.9" P.A. 224.00 sep 11.9 mag 7.68,10.15 Sp G5 dist. 26.27 pc (85.69 l.y.)

HU 885 AB: 508; 150x: Light orange stars, 2 Dm, 2" separation.  WDS says physical, however there is no parallax range overlap, -43%, it is not binary.
11h 06m 31.58s +14° 15' 44.3" P.A. 254.00 sep 2.1 mag 9.42,10.93 Sp K2V dist. 42.03 pc (137.1 l.y.)

A 2146 AB: 508; 600x: Very subtly notched elongation, fainter bump to SW.  WDS grade 4 orbit 94-year period.  No parallax data for the primary.
10h 12m 05.05s +21° 17' 54.6" P.A. 238.90 sep 0.2 mag 9.74,9.59 Sp F8 dist. 210.97 pc (688.18 l.y.)

STF1606 AB: 508; 300x: Close but clean split, white stears, slight magnitude difference.  WDS grade 4 orbit 1431-year period.  No Gaia parallax for the primary.
12h 10m 47.34s +39° 53' 29.5" P.A. 139.10 sep 0.6 mag 7.44,7.93 Sp A8III dist. 120.19 pc (392.06 l.y.)

HU 736 AB: 508; 600x: Hairline split, white stars, 1 Dm, with seeing.  WDS grade 4 orbit 245-year period.  No Gaia parallax data for the primary.
12h 16m 00.42s +48° 06' 58.4" P.A. 177.10 sep 0.3 mag 9.57,9.99 Sp F8 dist. 123.15 pc (401.72 l.y.)

HU 641 AB: 508; 550x: Excellent hairline split of faint stars, with seeing.  WDS grade 5 orbit 323-year period.  No Gaia data for the secondary.
12h 57m 53.94s +49° 48' 16.8" P.A. 290.30 sep 0.3 mag 10.30,10.30 Sp K3III

STT 278 AB: 508; 600x: Perfect airy discs, white stars, 1 Dm, a bit more than a hairline split.  WDS grade 3 orbit, 506-year period.  I don't find the Gaia data.
14h 12m 14.66s +44° 11' 22.5" P.A. 269.60 sep 0.4 mag 8.43,8.76 Sp F2IV dist. 192.68 pc (628.52 l.y.)

SWI 1 AB: 508; 150x: Ordinary equal 10th magnitude white stars, 3" separation.  This is a Lewis Swift double; better known for his deep sky discoveries, he has two other doubles, both in Draco.  WDS grade 4 orbit 1278-year period.  Sadly there is no parallax range overlap (-4%), so in spite of the very small 42 AU weighted separation, 0.4+0.4 Msol, it may not be binary.

14h 02m 33.18s +46° 20' 23.9" P.A. 25.70 sep 3.7 mag 10.05,10.26 Sp M2+M2.5

ES 608 AB: 508; 200x: Very lovely light yellow-orange A, 2 Dm B, closely split about 1".  HJ 2667 is a near an equal wide pair in the FOV 7' to the north.  WDS grade 5 orbit, 322-year period.  There is an 86% overlap of the pair's parallax ranges, a mere 43 AU weighted separation, and 0.5+0.4 Msol, only 72 ly distant, and surely a binary.
13h 37m 51.20s +48° 08' 17.2" P.A. 343.40 sep 1.4 mag 10.28,11.49 Sp M0.5+M1.5 dist. 22.14 pc (72.22 l.y.)

A 1102 AB: 508; 550x: Nice close split, near equal white stars.  Suspected at 300x.  WDS grade 4 orbit, 243-year period.  I don't find Gaia data for the primary.

14h 17m 52.83s +69° 14' 03.5" P.A. 77.60 sep 0.5 mag 9.33,8.65 Sp F2 dist. 182.48 pc (595.25 l.y.)

STF1621 AB: 508; 300x: 1 Dm, nearly 2" separation, light orange stars.  WDS grade 4 orbit, 1379-year period.  There is 83% overlap of their parallax ranges, only 45 AU weighted separation, 0.6+0.6 Msol, very likely a binary.
12h 15m 58.34s +05° 38' 24.8" P.A. 49.50 sep 1.8 mag 10.22,10.59 Sp K8 dist. 28.99 pc (94.57 l.y.)

STF1647 AB: 508; 200x: Near equal white stars, >1" separation.  WDS grade 4 orbit, 1010-year period.  However the stars do not share their parallax ranges, -8% overlap, so in spite of the mere 130 AU weighted separation and 1.5+1.4 Msol, it likely is not binary. 
12h 30m 33.75s +09° 42' 56.4" P.A. 249.50 sep 1.3 mag 8.09,8.37 Sp F2 dist. 92.51 pc (301.77 l.y.)

HU 138 AB: 508; 600x: Faint pair, near equal, well split when resolved to good discs with seeing.  WDS grade 4 orbit, 151.4-year period, it will tighten 0.1" in the next 20 years.  No Gaia parallax data for the primary.
14h 16m 00.46s -07° 03' 43.4" P.A. 216.60 sep 0.6 mag 9.80,9.79 Sp K0 dist. 68.73 pc (224.2 l.y.)

STF1876 AB: 508; 200x: Slightly unequal white stars, nice close split >1".  WDS grade 4 orbit, 966-year period, they unfortunately do not share their parallax ranges (-17% overlap), 104 AU weighted separation, 1.3+1.2 Msol, likely is not a binary.
14h 46m 21.64s -07° 22' 48.7" P.A. 114.80 sep 1.3 mag 8.46,8.62 Sp G0

A 2172 AB: 508; 600x: Out of round, but too tough to pin down a position angle, I guess south or east [actually ESE].  WDS grade 3 orbit, 168-year period, it will shift to the NE by the 2040s but become quite difficult to detect.  No Gaia parallax data for the primary.
14h 56m 30.89s +02° 55' 12.2" P.A. 116.60 sep 0.2 mag 8.00,8.60 Sp K0

A 2074 AB: 508; 600x: Overlapping discs / snowman at best moments, PA to the west, 1 Dm.  WDS grade 4 orbit, 59-year period.  At apastron now, it will close rapidly in the coming years and make a dramatic close pass in 2040. No Gaia parallax data for the primary.

15h 27m 20.82s +17° 38' 06.3" P.A. 269.30 sep 0.3 mag 8.55,9.37 Sp F8 dist. 90.74 pc (295.99 l.y.)

5 april 2022, leo doubles

Transparency was not very good last night, a typical warm weather marine haze settling in the Bay Area.  But seeing was pretty good, and I went after some challenge pairs in Leo with fairly good results.  Observed from 9:30pm to a bit after 11pm.  I experimented with 16-inch and 10-inch center masks, but since they were placed on the top of the mirror box they seemed to cause thermal seeing problems.  I may mount them at the top of the tube to see how they do.  The goal is better brightness and resolution with still a relatively small central obstruction.  As it was, I used my apodising mask throughout.

HDS1348 AB: 508; 150x: Obvious light yellow A and orange B, 2 Dm, wide about 9".  WDS says proper motion indicates physical.  There is 2% parallax range overlap, 281 AU weighted separation, 0.7+0.5 Msol, and the radial velocity delta 0.1 is less than the escape velocity 2.7, so it is very likely binary.
09h 23m 06.33s +22° 18' 20.4" P.A. 343.00 sep 8.3 mag 9.77,11.48 Sp M0 dist. 36.04 pc (117.56 l.y.)

COU1563 AB: 508; 150x: Nice near equal white stars, well separated, noticable Dm.  WDS uncertain, but there is -4% parallax range overlap, 930 AU weighted separation, 1.4+1.4 Msol, so not likely binary.
09h 23m 56.58s +32° 00' 22.6" P.A. 34.00 sep 2.5 mag 11.17,11.41

HU 869 AB: 508; 300x: Very fine white stars, 1 Dm, nicely split.  WDS uncertain, and no parallax data for the primary.
09h 25m 09.29s +14° 48' 36.2" P.A. 277.00 sep 0.7 mag 9.87,9.77 Sp K0

COU 935 AB: 508; 550x: Very faint haze resolves with seeing to a small point, 4 Dm and separated from the yellow-white A star.  WDS says physical, but there is -80% parallax range overlap, so it is not binary.
09h 26m 02.70s +18° 54' 02.2" P.A. 240.00 sep 0.9 mag 8.87,11.83 Sp A0 dist. 319.49 pc (1042.18 l.y.)

A 4 AB: 508; 550x: Light yellow-orange A and 2 Dm B, nicely separated around 1".  WDS uncertain, but there is -57% parallax range overlap, they are not binary.
09h 26m 17.45s +31° 08' 50.9" P.A. 37.00 sep 0.9 mag 9.59,10.69 Sp G0

COU1121 AB: 508; 300x: Very tough, very faint B seen with the best seeing, when light orange A tightens and B becomes resolves, separated around 1".  WDS uncertain, and there is -79% parallax range overlap, so they are not binary, in spite of the difficulty.

09h 28m 10.54s +28° 11' 21.8" P.A. 35.00 sep 1.0 mag 9.14,11.85 Sp K0 dist. 434.78 pc (1418.25 l.y.)

COU 936 AB: 508; 500x: Well separated around 1", white A and light orange B, 2 Dm.  WDS has 180.5-year period, it is currently near apastron.  However, Gaia shows -39% parallax range overlap, 70 AU weighted separation, 0.9+1.3 Msol -- so it is questionable whether this is binary at all.
09h 29m 00.67s +19° 17' 18.6" P.A. 224.40 sep 1.0 mag 8.42,9.96 Sp F5 dist. 83.13 pc (271.17 l.y.)

A 130 AB: 508; 300x: Quite a faint pair, slighy delta mag, needed best seeing for the 1" separation to settle.  WDS uncertain, however there is 25% parallax range overlap, 297 AU weighted separation, 1.2+1.2 Msol, so it is likely to be binary.

09h 30m 33.34s +20° 25' 48.6" P.A. 280.00 sep 1.0 mag 11.52,11.53

BU 909 AB: 508; 150x: Nice bright white A, B is very faint but plainly seen, well separated around 6".  WDS uncertain, but there is 50% parallax range overlap, 2,232 AU weighted separation, 3.5+1.2 Msol, so it is likely binary.
09h 32m 13.23s +21° 51' 23.1" P.A. 90.00 sep 6.2 mag 7.59,12.30 Sp K0III dist. 400 pc (1304.8 l.y.)

A 224 AB: 508; 150x: Well separated around 4", 1 Dm, light orange stars.  WDS says not physical, and there is -68% parallax range overlap.
09h 32m 08.01s +30° 26' 55.1" P.A. 145.00 sep 4.0 mag 10.20,11.17 Sp G

HO 368 AB: 508; 150x: White stars, significant delta mag, nice close split <2".  WDS uncertain, but there is 49% parallax range overlap, only 341 AU weighted separation, 1.4+1.6 Msol, so it is likely binary.
09h 37m 25.28s +25° 21' 36.8" P.A. 112.00 sep 1.4 mag 10.05,10.61 Sp F2

A 2479 AB: 508; 600x: Hairline split at the best moments, 1 Dm, PA WSW.  Short 108-year period, it is to make a slow rotation and tighten to the NW by 2040.  No parallax data for the B star.
09h 37m 38.81s +15° 27' 30.7" P.A. 257.60 sep 0.3 mag 9.23,9.87 Sp F8 dist. 174.52 pc (569.28 l.y.)

COU1254 Ba-Bb: 508; 550x: Very finely split, half delta mag, light yellow-white stars.  Component of ARY 51 AB, which is a super-wide separation pair.  WDS uncertain, and unfortunately there is no parallax data for either star.

09h 38m 50.20s +30° 16' 38.0" P.A. 88.00 sep 0.6 mag 10.32,10.12 Sp G0

COU 283 AB: 508; 550x: White stars, near equal, hairline split with the best seeing.  WDS uncertain, and there is no parallax data for the B star.
09h 42m 34.48s +19° 58' 01.7" P.A. 52.00 sep 0.6 mag 10.18,10.42 Sp F0

COU 776 AB: 508; 300x: Nicely split around 1", near equal, white.  WDS uncertain, but there is -21% parallax range overlap, in spite of the 293 AU weighted separation and 1.4+1.4 Msol, it is not likely binary.
09h 45m 45.65s +25° 00' 29.0" P.A. 245.00 sep 1.0 mag 10.84,11.01 Sp F8

COU 285 AB: 508; 600x: Exceptionally fine split with seeing, 1 Dm, light orange stars, very tough.  WDS uncertain, and there is no Gaia data for the B star.
09h 49m 53.92s +19° 47' 05.0" P.A. 187.00 sep 0.5 mag 9.80,10.70 Sp G5

AG 340 AB: 508; 150x: Near equal white stars, well separated around 5".  WDS uncertain, and there is no Gaia data for the primary.
09h 50m 28.65s +26° 02' 25.1" P.A. 310.00 sep 4.8 mag 10.10,10.60

COU 49 AB: 508; 200x: Fine pair, 1 Dm, well separated.  GII 80 not seen, near equal 0.2" to the B star.  WDS uncertain, and unfortunately no Gaia data for the B star.

09h 50m 54.20s +20° 15' 25.0" P.A. 357.00 sep 2.2 mag 10.30,11.10

A 344 AB: 508; 300x: Hairline split, slight delta mag, yellow-white stars.  WDS uncertain, and there is no Gaia data for the B star. 
09h 52m 06.88s +29° 15' 52.2" P.A. 68.00 sep 0.7 mag 9.63,9.96 Sp F8