29 september 2020

There are new fires in California, throwing ever more smoke into the air.  Most of it has gone over the ocean, and with some luck we had a wind from the south push it all north of us.  It was clear enough to observe for most of the night, but a foggy haze built up through the night, illuminated by the full moon which spread a bright glow all around.  Seeing was variable, generally getting better through the session but there were times when it was really unstable.  Overall a good night with many interesting pairs.  I ended the night looking at Mars, which was getting fairly high, and saw a wealth of detail around the Mare Erythraeum and surrounds, including bright mountains of Noctis Labyrinthus.  Observed from 8:30pm to midnight.

STT 426 AB: 508; 205x: 60 Cyg. Brilliant white A and much fainter ashen B, close ~2" but well split.
21H 01M 10.93S +46° 09' 20.8" P.A. 159 SEP 2.9 MAG 5.40,9.53 SP B1VE DIST. 467.29 PC (1524.3 L.Y.)

HO 600 AB: 508; 333x: Light yellow orange A star, and very faint greyish B star appears ~2" separated.  Suspected with 205x, but needed 333x and apodising mask to reduce A's disk size to clearly resolve it.
21H 01M 47.44S +44° 11' 13.6" P.A. 97 SEP 2.1 MAG 6.70,10.90 SP AM DIST. 70.13 PC (228.76 L.Y.)

BU 156 AB: 508; 533x: Using apodising mask.  Extraordinarily fine, B is a tiny faint point where light orange A's first diffraction ring would be -- ~1" -- but I need the diffraction ring to disappear, with seeing, to resolve it.  1.2" at discovery at 1873 with his 6-inch!
21H 00M 49.84S +46° 34' 42.8" P.A. 235 SEP 0.9 MAG 7.37,9.24 SP B5V DIST. 341.3 PC (1113.32 L.Y.)

COU 2650 AB: 508; 205x: Very significant delta mag, ~1 delta or more, ~2", white stars, very fine 

21H 01M 52.59S +48° 02' 19.4" P.A. 255 SEP 1.9 MAG 10.57,11.40

BU 1138 AB: 508; 1067x: Notched elongation with seeing and apodising mask, white, can tell A and B's orientation by difference in magnitude.  Current separation 0.155".  314 year period, it will only make modest position angle change in my time.  Burnham discovered in 1888 with the Lick 36-inch at 0.3"!  It seems Hough also discovered it in 1888 but published his results later, HO 282.

21H 02M 48.62S +45° 50' 56.0" P.A. 181.8 SEP 0.155" MAG 7.10,7.30 SP B3VN DIST. 400 PC (1304.8 L.Y.)

STF 2757 AB: 508; 205x: Very attractive white A and light yellow B, ~2", ~2 delta mag. 

21H 04M 34.72S +52° 23' 59.2" P.A. 264 SEP 1.9 MAG 7.82,9.24 SP B9.5V DIST. 227.79 PC (743.05 L.Y.)

ES 96 AB: 508; 205x: ! Extremely faint companion on edge of direct vision, wide separation.  White stars, very large delta mag.  Not physical. 

21H 04M 35.43S +50° 28' 13.7" P.A. 253 SEP 8.2 MAG 8.28,12.20 SP A1V DIST. 272.48 PC (888.83 L.Y.)

BU 680 AB: 508; 333x: Finely split, slight magnitude difference.  C is very wide and ~2 delta. Very nice pair.  Discovered in 1877 with the Dearborn 18.5-inch at 0.5"
21H 05M 30.82S +53° 40' 05.5" P.A. 284 SEP 0.6 MAG 8.70,9.38 SP A0 DIST. 335.57 PC (1094.63 L.Y.)

BU 158 AB: 508; 205x: Bright white A star and faint B star, just visible with direct vision, widely separated. In same field of view planetary nebula NGC 7026, fairly bright considering full moon and haze, rectangular with diffuse edges and strings of nebulosity stretching from either side.  It is close a light orange star (TYC 3592-2787-1, 9.59v).  
21H 05M 43.99S +47° 48' 17.0" P.A. 304 SEP 11 MAG 7.45,12.00 SP B9V DIST. 247.52 PC (807.41 L.Y.)

ES 816 AB: 508; 205x: Faint white pair, near equal, well separated.  Not physical.
21H 05M 33.29S +47° 58' 10.2" P.A. 36 SEP 2.6 MAG 9.86,10.83

BU 679 AB: 508; 533x: Very tough faint pair, poor transparency not helping, appears as a hazy elongation most of the time but it does tighten & resolve with seeing, close split.  Burnham: "This close and exceedingly minute pair was discovered with the [Dearborn] 18.5-inch" in 1878 at an astonishing 0.38"
21H 05M 50.42S +43° 40' 54.0" P.A. 75 SEP 0.7 MAG 11.50,11.90

A 1691 Aa-Ab: 508; 533x: Extremely tough, marginal, a fleeting brightening within first diffraction with seeing, only intermittently.  Tried foveal coaxing and all my other tricks.

21H 06M 00.69S +54° 21' 54.5" P.A. 276 SEP 0.7 MAG 9.20,13.20 SP F8

ES 2705 AB: 508; 205x: Blue-white A and ruddy ~2 delta mag B, wide.  Not physical
21H 06M 13.61S +53° 07' 34.3" P.A. 19 SEP 9 MAG 9.55,10.10 SP A7

BU 836 AB: 508; 333x: Suspected at 205x, better view at 333x.  Very fine split, faint pair, nearly 1 delta mag.  Burnham: "The principal pair was discovered with the 15.5-inch of the Washburn Observatory, and it was then stated that C might also be double.  This was verified with the 36-inch in 1888, thus making a pretty but difficult quadruple group."  Unfortunately I didn't bother with the AC pair since it was widely separated, so I missed observing CD 11.28/12.30 1.4" (1.2" when suspected at Washburn & later verified at Lick).  Amazing.
21H 06M 32.69S +48° 23' 12.4" P.A. 177 SEP 0.8 MAG 9.98,9.64 SP A

ES 512 AB: 508; 205x: Faint B star, wide, brilliant white A, dense field.  Not physical

21H 08M 57.85S +47° 16' 15.6" P.A. 2 SEP 13.4 MAG 7.01,12.30 SP F3III DIST. 68.49 PC (223.41 L.Y.)

TDT 2786 AB: 508; 1067x:  Light orange star, subtle elongation only at all powers up to 1067x, I think it is <0.2".  Listed in SkyTools using 1991 measure at 0.4" and 0.7" in Stelle Doppie using 2007 measure.  Maybe its period is so short it's only a few years to tighten?  
21H 09M 09.30S +47° 36' 52.8" P.A. 240 SEP 0.7 MAG 10.11,10.54

COU 2545 AB: 508; 333x: Nice, very clean split, near equal white stars, an attractive pair 

21H 09M 43.58S +48° 20' 39.3" P.A. 74 SEP 0.7 MAG 10.68,10.65

SMA 128 AB: 508; 205x: Bright white A star and faint companion, wide
21H 09M 46.42S +46° 23' 37.5" P.A. 170 SEP 12.3 MAG 8.42,11.40 SP B3IV

A 884 AB: 508; 533x: Excellent pair, nicely split, nearly 1 delta mag, white A and blue-white B

21H 13M 20.32S +46° 54' 55.5" P.A. 114 SEP 0.4 MAG 8.72,9.48 SP F0

COU 2299 AB: 508; 1067x: Hairline split at 667x, no question steady split with 1067x.  Light orange-yellow stars, nearly one delta.
21H 13M 56.67S +44° 00' 16.9" P.A. 43 SEP 0.3 MAG 9.16,9.37 SP F5

AGC 13 AB: 203; 667x: Tau Cyg.  I get a persistent brightening in A's diffraction.  The brightening holds steady in one spot of A's diffraction wobble, and it's a different color: orange compared with A's yellow-white.  Needed the 8-inch mask to reduce A's disk size.
21H 14M 47.49S +38° 02' 43.1" P.A. 187.9 SEP 0.99 MAG 3.83,6.57 SP F3V+F7V DIST. 20.34 PC (66.35 L.Y.)

ES 147 AB: 508; 205x: Close pair, bright white A and yellow B, ~3" and ~2 delta mag.  Busy field with other possible wide pairs. [4 stars in the uncertain system.]

22H 24M 28.46S +54° 52' 03.7" P.A. 25 SEP 2.6 MAG 8.55,10.57 SP B9

A 1463 AB: 508; 533x: Split with 333x but had a better look with 533x, light orange stars, well split, 1" ~2 delta.  Good pair 

22H 25M 40.03S +56° 30' 34.1" P.A. 336 SEP 1.1 MAG 8.73,9.83 SP K0

ES 687 AB: 508; 205x: Near equal wide, white.  Physical.
22H 25M 38.72S +48° 07' 43.5" P.A. 267 SEP 4.4 MAG 9.45,9.88 SP A3

LEO 53 AB: 508; 205x: Bright yellow A and very faint B is noticed right away, well separated.  Not physical

2H 29M 53.47S +52° 24' 59.6" P.A. 298 SEP 13 MAG 6.63,11.50 SP G8III DIST. 124.07 PC (404.72 L.Y.)

HU 1318 AB: 508; 333x: Suspected at 205x, nice clean split at 333x, white near equal stars. Physical
22H 29M 59.61S +51° 22' 10.2" P.A. 13 SEP 1 MAG 9.86,9.92 SP A0

ES 1022 AB: 508; 205x: Faint pair, ~1 delta mag, wide split.  Not physical
22H 30M 05.36S +54° 04' 59.1" P.A. 131 SEP 6.5 MAG 10.32,11.31 SP F0V

STF 2917 AB: 508' 205x: White near equal, well split.  Physical
22H 30M 35.57S +53° 31' 43.3" P.A. 70 SEP 4.9 MAG 8.28,8.56 SP F0IV DIST. 374.53 PC (1221.72 L.Y.)

HLD 54 AB: 508; 205x: Easy pair, should have been a Struve.  White stars, ~1 delta, ~2" 

22H 50M 40.50S +51° 06' 57.8" P.A. 17 SEP 1.9 MAG 8.74,9.55 SP A0 DIST. 568.18 PC (1853.4 L.Y.)

BU 1332 AB: 508; 205x: Fine pair, white stars, near equal, >1"  
22H 50M 55.99S +53° 02' 38.3" P.A. 129 SEP 1.6 MAG 9.26,9.53 SP F2

ES 1032 BC: 508; 333x: AB is no problem, A bright yellow and B faint and wide.  BC is very cool, very faint, split ~2", near equal, seen directly but brightens with averted vision.
22H 51M 49.40S +53° 11' 08.6" P.A. 181 SEP 2.2 MAG 13.82,14.00 DIST. 106.16 PC (346.29 L.Y.)

ES 925 AB: 508; 205x: Easy wide, ~2 delta mag.  Not physical.

23H 18M 02.55S +49° 51' 37.6" P.A. 64 SEP 6.2 MAG 9.55,10.40 SP G5

A 202 AB: 508; 205x: Pretty blue-white A and slightly buff B,  ~2 delta mag, wide.  Not physical
23H 18M 23.56S +47° 15' 41.9" P.A. 257 SEP 2.7 MAG 9.00,10.46 SP B9II DIST. 243.9 PC (795.6 L.Y.)

ES 1042 AB: 508; 205x: Easy wide dull white pair, significant mag difference.  Not Physical
23H 18M 44.12S +52° 44' 08.5" P.A. 313 SEP 3 MAG 10.20,10.78

STT 493 AB: 508; 205x:  3 relatively bright stars in a wide triangle, this one the faintest of the bunch, with a faint ~3 delta mag wide companion. 
23H 18M 56.99S +48° 29' 45.2" P.A. 25 SEP 8.3 MAG 7.67,10.66 SP A8II DIST. 223.71 PC (729.74 L.Y.)

A 639 AB: 508; 333x: Suspected at 205x, split with seeing at 333x, white stars, significant magnitude difference ~1 delta, a bit less than 1".   

23H 19M 02.87S +47° 26' 12.7" P.A. 103 SEP 0.8 MAG 10.68,10.83 SP G5

ES 108 AB: 508; 205x: Lies in the middle of an arc of three stars, the pair is well separated white stars with slight delta mag.

23H 25M 38.60S +52° 40' 59.7" P.A. 245 SEP 2.7 MAG 10.29,9.76