Wednesday, March 9, 2022

6 march 2022

Continued my march through Struve pairs, this time mainly Cancer and Hydra.  I finished with a string of BUs in Hydra.  Overall the BUs are consistently more challenging, and therefore more exciting, than the STFs, so I'll always make room for them.  Seeing with the 7-inch was very good, 8/10, but it didn't quite support 20-inches.  There was a marine haze and dew throughout, a little cold.  Observed from 9-11pm.

STF1324 AB: 178; 300x: 2 Dm B appears with averted vision at first, then can hold direct, well split.  WDS says physical, however there is no overlap of the parallax ranges -14%, so not likely binary.
09h 14m 00.43s +26° 10' 34.8" P.A. 349.00 sep 11.5 mag 9.30,10.95 Sp K0 dist. 423.73 pc (1382.21 l.y.)

STF1301 AB: 178; 150x: White stars, 1 Dm, wide.  WDS uncertain, but there is -46% overlap in parallax ranges, so they are not binary.
09h 01m 56.20s +26° 12' 15.7" sep 10.1 mag 9.63,10.32 Sp F8 dist. 136.61 pc (445.62 l.y.)

STF1288 AB: 178; 150x: Near equal white stars, wide.  WDS says parallax indicates physical, and there is 18% parallax range overlap, 936 AU weighted separation, 1.1+1.1 Msol, and the radial velocity delta 0.2 is less than the escape velocity 3.0, so it is binary.  
08h 52m 45.13s +28° 27' 29.2" P.A. 259.00 sep 7.7 mag 10.16,10.17 Sp G0

STF1265 AB: 178; 150x: White stars, almost 2 Dm, one of a corner of a equal mangitude white stars forming an equilateral triange.  WDS says not physical, however there is 69% overlap of parallax ranges, only 596 AU weighted separation, with 1.4+0.9 Msol, so the probability is high these are binary, though the proper motion is divergent it may simply be due to the orbital direction.
08h 43m 52.93s +13° 37' 26.2" P.A. 312.00 sep 5.7 mag 8.70,10.33 Sp G5 dist. 111.11 pc (362.44 l.y.)

STF1287 AB: 178; 150x: Tightly split 2 Dm pair, rather difficult but well seen, white stars.  WDS uncertain, but there is no overlap -35% of the parallax ranges, so they are not binary.
08h 51m 27.31s +12° 07' 40.5" P.A. 93.00 sep 2.1 mag 8.28,10.17 Sp F0

STF1319 AB: 178; 150x: White A and 2 Dm wide B, faint for a Struve.  WDS uncertain, but there is -28% parallax range overlap, so they are not binary.
09h 11m 08.51s +08° 34' 49.4" P.A. 50.00 sep 13.5 mag 10.03,11.87 Sp K5

STF1237 AB: 178; 150x: 3 Dm and very wide.  WDS says not physical, and there is -77% parallax range overlap, so they are not.
08h 30m 43.06s +08° 25' 54.4" P.A. 173.00 sep 5.5 mag 10.20,13.00 Sp A2

BU 585 AB: 178; 300x: Very slightly notched snowman, difficult.  WDS uncertain, and no Gaia data on the pair.
08h 41m 15.31s +20° 28' 36.8" P.A. 72.00 sep 0.3 mag 7.10,8.08 Sp A0III dist. 167.5 pc (546.38 l.y.)

STF1385 AB: 178; 300x: I see a brighter part of the diffraction which is in the correct PA, but this is very tentative. Tried 150-600x.  WDS is physical, but there is no Gaia data for the B star.
09h 49m 57.94s +16° 33' 35.4" P.A. 330.00 sep 1.0 mag 9.01,10.63 Sp G0 dist. 149.25 pc (486.85 l.y.)

STF1390 AB: 178; 150x: Very fine 1 Dm white A and blue B, nicely split about 2".  WDS uncertain, but there is 41% overlap in parallax ranges, 968 AU weighted separation, 2.4+2.0 Msol, so it is likely binary.  The AC pair is SE 5 and it has 32% parallax overlap, 5,711 AU weighted separation, 2.0+1.4 Msol, so this may also be a physical triple.
09h 52m 08.54s +16° 27' 46.8" P.A. 207.00 sep 2.2 mag 9.31,10.12 Sp B9 dist. 366.3 pc (1194.87 l.y.)

STF1396 AB: 178; 150x: White A and orange B, 2 Dm, well split around 4".  WDS uncertain, however there is 77% overlap in the parallax ranges, 1,315 AU weighted separation, and 2.4+1.7 Msol, so it is likely binary.
09h 56m 22.21s +10° 39' 55.5" P.A. 131.00 sep 3.9 mag 8.79,10.42 Sp A0 dist. 595.24 pc (1941.67 l.y.)

STF1397 AB: 178; 300x: Very fine split, almost 2 Dm.  WDS certain, and there is no Gaia data for the B star.
09h 56m 44.80s +25° 03' 14.1" P.A. 96.00 sep 1.1 mag 9.33,10.62 Sp G0 dist. 263.16 pc (858.43 l.y.)

STF1392 AB: 178; 150x: B is faint, first seen with averted vision and then can hold direct, 2 Dm, white stars, wide.  WDS uncertain, there is 4% overlap of parallax ranges, 2,836 AU weighted separation, and 1.7+1.2 Msol, so there is some chance they are binary.
09h 56m 03.71s +29° 05' 54.8" P.A. 176.00 sep 9.4 mag 9.93,12.60 Sp G5

STF1308 AB: 178; 150x: Ordinary yellow-white stars, 1 Dm, wide.  WDS says proper motion indicates physical, however there is -55% overlap in parallax ranges, so they certainly are not binary.
09h 04m 59.50s -03° 59' 15.1" P.A. 85.00 sep 10.9 mag 8.09,9.19 Sp F5 dist. 122.55 pc (399.76 l.y.)

STF1307 AB: 178; 150x: B is very faint, seen with averted vision only, wide.  WDS says not physical, and with -91% parallax range overlap, they are corred.
09h 04m 28.14s +04° 50' 16.1" P.A. 314.00 sep 8.6 mag 9.49,13.50 Sp K0

STF1309 AB: 178; 150x: Equal, white, wide.  WDS says proper motion & parallax indicate physical, however there is -38% parallax range overlap, they are not binary!  
09h 06m 38.25s +02° 49' 06.3" P.A. 273.00 sep 11.7 mag 8.48,8.38 Sp F4V+F6IV dist. 97.94 pc (319.48 l.y.)

STF1343 AB: 178; 150x: Equal, white, wide.  WDS says parallax indicates physical, and there is 9% parallax range overlap, 394 AU weighted separation, 0.8+0.8 Msol, and the radial velocity delta 1.7 is less than the escape velocity 2.6, so they likely are binary.
09h 19m 58.34s +04° 59' 58.6" P.A. 275.00 sep 9.1 mag 9.37,9.59 Sp G5

STF1329 AB: 178; 150x: Equal, white, wide.  WDS proper motion indicates not physical, and they are divergent, but more importantly there is -98% parallax range overlap, so definitely not binary. 
09h 15m 43.02s -01° 14' 29.9" P.A. 266.00 sep 8.2 mag 9.16,9.17 Sp G5

STF1316 AB: 178; 150x: Nice!  It's a triple system which forms an arc, the C being 1 magnitude brighter than the slightly closer B.  WDS says proper motion indicates physical, and there is 22% overlap in the parallax ranges, 479 AU weighted separation, and 1.1+0.7 Msol.  But the radial velocity delta 5.9 exceeds the escape velocity 2.6, so it may not be a binary.
09h 07m 52.48s -07° 08' 19.9" P.A. 137.00 sep 7.2 mag 8.80,10.70 Sp G0 dist. 64.64 pc (210.86 l.y.)

STF1357 AB: 178; 150x: Nice!  2 Dm B to bright white A, about 4" separation.  WDS uncertain, but the parallax range overlap is -2%, 1,606 AU weighted separation, 3.1+1.4 Msol, and the radial velocity delta 2.5 is slightly higher than the escape velocity 2.2, so likely not binary.
09h 28m 20.52s -09° 59' 12.8" P.A. 54.00 sep 7.7 mag 6.94,9.85 Sp K0 dist. 242.72 pc (791.75 l.y.)

STF1367 AB: 178; 150x: Pretty pair, white A and yellow B, well split, 2 Dm.  WDS says parallax indicates physical, but in fact there is no overlap of the parallax ranges, -62%, so it is definitely not physical.
09h 32m 11.78s -10° 50' 37.2" P.A. 184.00 sep 5.6 mag 7.93,8.99 Sp G0

STT 197 AB: 178; 205x: Excellent pair, about 2 Dm and closely split at 150x, better seen at 205x.  It sits at the top of a Christmas tiangle asterism.  WDS uncertain, but there is 20% parallax range overlap, a small 263 AU weighted separation, and 2.2+1.7 Msol -- so this is likely binary. 
09h 09m 31.08s +02° 56' 28.7" P.A. 65.00 sep 1.4 mag 7.92,9.03 Sp F1V dist. 164.74 pc (537.38 l.y.)

BU 104 AB: 178; 205x: Yellow-white A (spectral class K2III yellow-orange) and very much fainter B appears very closely split, <2".  I needed averted vision to see the B star at first, but could then hold it direct.  WDS says physical, but there is no parallax range overlap, -17%, so it is not likely to be binary.  Burnham discovered with his 6-inch.
09h 11m 29.26s +00° 17' 28.5" P.A. 105.00 sep 3.3 mag 6.99,10.64 Sp K2III dist. 228.31 pc (744.75 l.y.)

BU 211 AB: 178; 150x: Wow!  Exceptionally fine split, 2 Dm, with best seeing and perfect focus.  WDS uncertain, and there is no Gaia data for the B star.  Burnham discovered with his 6-inch.
09h 01m 58.78s +02° 40' 16.3" P.A. 270.00 sep 1.1 mag 7.34,8.77 Sp A2 dist. 147.49 pc (481.11 l.y.)

BU 212 AB: 178; 150x: Beatuiful, clean split, 1 Dm.  WDS uncertain, but there is no parallax range overlap, -4%, so it is not likely binary.  Burnham discovered with his 6-inch.
09h 16m 04.39s -08° 21' 01.8" P.A. 198.00 sep 1.6 mag 7.80,8.34 Sp A5 dist. 130.55 pc (425.85 l.y.)

BU 213 AB: 178; 205x: Very nice 2 Dm, very closely split with 150x, better at 205x.  WDS is uncertain, but there is -84% parallax range overlap, so they are not binary.  Burnham discovered with his 6-inch.
09h 28m 20.37s -08° 05' 18.2" P.A. 171.00 sep 1.9 mag 8.31,10.18 Sp A0 dist. 248.14 pc (809.43 l.y.)

BU 214 AB: 178; 150x: Very nice, 2 Dm, well split, white.  WDS says not physical, but there is 99% parallax range overlap, small 283 AU weighted separation, 1.5+0.9 Msol, so this is certainly binary.  Burnham discovered with his 6-inch.
09h 41m 29.89s -18° 29' 00.2" P.A. 243.00 sep 3.6 mag 7.73,9.64 Sp F7V dist. 55.28 pc (180.32 l.y.)

BU 216 AB: 178; 150x: Bright whtie A and much fainter B, well separated, very low, I was lucky to get this in a gap between trees.  WDS uncertain, but there is -13% parallax range overlap, so not likely to be binary.
09h 56m 46.89s -26° 32' 59.1" P.A. 153.00 sep 3.7 mag 6.31,10.50 Sp A4V dist. 67.52 pc (220.25 l.y.)

BU 336 AB: 178; 150x: Superfine split, significant delta mag, nice!  WDS uncertain, but there is -58% parallax range overlap, so they are not binary.  
09h 11m 46.52s -16° 48' 44.9" P.A. 240.00 sep 1.9 mag 8.89,9.99 Sp A1/2IV/V

BU 337 AB: 178; 150x: 3 Dm, wide.  WDS says physical, but there is no parallax range overlap -97%, and the radial velocity delta 18.8 far exceeds the escape velocity 2.1, so it is definitely not binary. 
09h 22m 29.38s -17° 53' 38.6" P.A. 352.00 sep 9.9 mag 7.00,10.18 Sp F4V dist. 101.73 pc (331.84 l.y.)

BU 338 AB: 178; 150x: White A and 2 Dm wide B.  WDS says physical, and there is 19% parallax range overlap, 511 AU weighted separation, 1.2+0.8 Msol, so it is probably binary.  Burnham discovered with his 6-inch.
09h 22m 56.62s -15° 29' 44.4" P.A. 273.00 sep 7.2 mag 8.44,10.35 Sp F7/8V dist. 82.71 pc (269.8 l.y.)

BU 339 AB: 178; 300x: Incredibly fine split about 1.5", 1 Dm.  WDS phsyical with 1111-year period, but there is -41% parallax range overlap, so it is probably not binary at all!
09h 30m 57.03s -15° 44' 19.6" P.A. 251.90 sep 1.2 mag 8.95,9.76 Sp F6/7V dist. 131.75 pc (429.77 l.y.)

BU 409 AB: 178; 150x: Pretty white A and blue B, 1 Dm, well separated.  WDS uncertain, but there is 28% parallax range overlap, 1,557 AU weighted separation, 2.3+1.2 Msol, so it is probably binary.  Burnham discovered with his 6-inch.
09h 00m 45.63s -09° 11' 29.1" P.A. 187.00 sep 9.8 mag 7.25,10.10 Sp A0 dist. 167.22 pc (545.47 l.y.)

BU 588 AB: 178; 150x: Superfine split, faint B, only with seeing, well split about 2".  WDS uncertain, but there is no parallax range overlap -12%, so it is not likely binary. 
09h 16m 40.03s +00° 43' 44.7" P.A. 166.00 sep 2.4 mag 6.50,11.00 Sp F1V dist. 68.26 pc (222.66 l.y.)

BU 455 AB: 178; 205x: Very beautiful, light yelow A and 2 Dm B, about 2" separation.  WDS uncertain, but there is no parallax range overlap, -81%, so it is not binary.
09h 14m 51.46s +04° 12' 38.1" P.A. 68.00 sep 1.8 mag 8.14,9.88 Sp K0 dist. 311.53 pc (1016.21 l.y.)

BU 908 BC: 508; 205x: The AB pair is wide, near equal.  BC was suspected as double with 7-inch, but I needed 20-inch aperture to split this very faint pair.  WDS uncertain, but there is no parallax range overlap, -50%, so it is not binary.
09h 14m 18.37s -08° 17' 34.3" P.A. 233.00 sep 0.9 mag 10.73,10.80

BU 592 AB: 178; 150x: Bright white A and faint wide B.  WDS uncertain, but there is 62% overlap of the parallax ranges, 1,738 AU weighted separation, and 3.0+0.9 Msol.  Further, the radial velocity delta 0.3 is less than the escape velocity 2.0, so it is very likely to be binary.
09h 55m 00.14s -16° 11' 38.1" P.A. 193.00 sep 9.7 mag 6.62,12.10 Sp K0III dist. 202.84 pc (661.66 l.y.)

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