I used the 20-inch the rest of the night, from 9:30pm to 12:15am. It was a good steady night, 8/10 at high magnifications during the start of the night, degrading a bit after 11pm. There was a haze in the sky, from both water vapor and high smoke -- the airliners on approach to Oakland airport cast light beams ahead of them. I'm sure it hurt some of the fainter pairs, but the seeing made up for it. I had some interruptions with the ServoCAT motors, it cuts out when moving in azimuth -- some kind of kink in the gear or electrical signal -- I'll have to check that.
I ended the night looking at Mars at 333x, with both the 8-inch mask and at full 20-inch, with apodising mask. A really small, sharp bright white polar cap, and I could see wonderful darker swirls in the mountains. A bit awkward to view this in the 20-inch, pointed over the eastern fence--hence the 6-inch refractor.
BU 287 AB: 508; 205x: Deneb el okab. B quite easily seen as a faint companion to brilliant white A, wide ~7", very large delta mag. Burnham discovered it with the 26-inch at the USNO in 1874 during a short stint there -- at 5.53" so it was tougher and probably needed that aperture to discover.
BU 287 AB: 508; 205x: Deneb el okab. B quite easily seen as a faint companion to brilliant white A, wide ~7", very large delta mag. Burnham discovered it with the 26-inch at the USNO in 1874 during a short stint there -- at 5.53" so it was tougher and probably needed that aperture to discover.
19H 05M 24.61S +13° 51' 49.4" P.A. 46 SEP 7.2 MAG 2.96,12.00 SP A0VN DIST. 25.46 PC (83.05 L.Y.)
HEI 275 AB: 508; 553x: Very fine but definite split, near equal, white. Discovered by W.D. Heintz in 1984 with the Swarthmore College 61-cm refractor; only four observations in WDS so no firm orbit has been determined.
HEI 275 AB: 508; 553x: Very fine but definite split, near equal, white. Discovered by W.D. Heintz in 1984 with the Swarthmore College 61-cm refractor; only four observations in WDS so no firm orbit has been determined.
20H 20M 49.74S +13° 27' 13.7" P.A. 92 SEP 0.3 MAG 10.61,10.45 SP A2
COU 327 AB: 508; 1067x: The AB-C pair is easy at 205x, C is a faint star ~4" separated from bright A (8.41/11.97 4.0"). AB is much more difficult. At 1067x it is mostly overlapping disks & I can tell its orientation. But at repeated best moments, I get an instant of the finest hairline split with noticeable magnitude difference & I can estimate an orientation relative to nearby stars. It's PA [246°] is nearly perpendicular to AB-C [131°] -- this is how I confirmed I have it. Cocteau discovered it in 1968 with the Nice 30-inch refractor at 0.2". 42.46 year period, last observation in 2005, with grade 3 orbit (which is certain but not definitive). It is currently coming off apastron with the current orbital solution at 0.167" separation. It will tighten very rapidly the next few years, but even on the opposite side of it's orbit it will not be detectable by me, I need to wait until 2050 to try again -- but since the PA will be similar I won't notice that change. I can only look forward to the tightening and maybe detectability again. If is the 0.167" is correct I have exceeded the Raleigh, Dawes, and Sparrow criteria and it's a new personal best -- and given I did not split some similar pairs later in the night, I was very lucky with the seeing at the time of the observation.
COU 327 AB: 508; 1067x: The AB-C pair is easy at 205x, C is a faint star ~4" separated from bright A (8.41/11.97 4.0"). AB is much more difficult. At 1067x it is mostly overlapping disks & I can tell its orientation. But at repeated best moments, I get an instant of the finest hairline split with noticeable magnitude difference & I can estimate an orientation relative to nearby stars. It's PA [246°] is nearly perpendicular to AB-C [131°] -- this is how I confirmed I have it. Cocteau discovered it in 1968 with the Nice 30-inch refractor at 0.2". 42.46 year period, last observation in 2005, with grade 3 orbit (which is certain but not definitive). It is currently coming off apastron with the current orbital solution at 0.167" separation. It will tighten very rapidly the next few years, but even on the opposite side of it's orbit it will not be detectable by me, I need to wait until 2050 to try again -- but since the PA will be similar I won't notice that change. I can only look forward to the tightening and maybe detectability again. If is the 0.167" is correct I have exceeded the Raleigh, Dawes, and Sparrow criteria and it's a new personal best -- and given I did not split some similar pairs later in the night, I was very lucky with the seeing at the time of the observation.
20H 21M 35.69S +19° 29' 40.1" P.A. 246.1 SEP 0.17 MAG 9.10,9.10 SP F8 DIST. 188.68 PC (615.47 L.Y.)
HEI 77 AB: 508; 205x: Very fine near equal white pair, really nice.
20H 39M 15.21S +15° 31' 29.5" P.A. 41 SEP 1.4 MAG 10.91,10.72
20H 39M 15.21S +15° 31' 29.5" P.A. 41 SEP 1.4 MAG 10.91,10.72
HU 362 AB: 508; 333x: Hairline split, white, near equal. Very nice pair.
20H 39M 29.33S +18° 56' 55.3" P.A. 312 SEP 0.7 MAG 9.40,9.78 SP K2
HEI 278 AB: 508; 333x: Easy wide, near equal.
20H 40M 31.91S +12° 40' 15.6" P.A. 135 SEP 3.4 MAG 11.06,11.10
HDS2947 AB: 508; 1067x: With apodising mask. Not round is best I can say; marginal. Coming off apastron and only getting more difficult. Discovered 1991 by the Hipparcos satellite at 0.2".
20H 40M 35.25S +15° 38' 35.3" P.A. 118.1 SEP 0.155 MAG 7.27,8.14 SP F5 DIST. 71.63 PC (233.66 L.Y.)
HDS2947 AB: 508; 1067x: With apodising mask. Not round is best I can say; marginal. Coming off apastron and only getting more difficult. Discovered 1991 by the Hipparcos satellite at 0.2".
20H 40M 35.25S +15° 38' 35.3" P.A. 118.1 SEP 0.155 MAG 7.27,8.14 SP F5 DIST. 71.63 PC (233.66 L.Y.)
J 191 AB: 508; 205x: Well split, >1", half delta mag, slight color difference of very light blue and orange. Discovered 1895 at 4.5", it has tightened considerably, through binarity is uncertain.
20H 40M 52.16S +17° 37' 59.2" P.A. 167 SEP 1.3 MAG 10.90,11.20
COU 226 AB: 508; 533x: Wow really nice 2+1 system. The +1 is a faint wide star (AC, 8.58/11.50, 13.5"). The AB is a very tight double, ~0.5", split, white, near equal.
20H 41M 51.24S +19° 31' 13.6" P.A. 54 SEP 0.4 MAG 8.00,8.30 SP A2
MLB 620 AB: 508; 205x: ~2 delta mag, wide, white A and ruddy B
21H 36M 06.03S +27° 16' 15.4" P.A. 243 SEP 7.5 MAG 9.80,10.80 SP G0
HO 165 AB: 508; 333x: Beautiful close split, ~1 delta mag white stars, <1". Suspected at 205x.
21H 42M 34.56S +18° 59' 37.2" P.A. 63 SEP 0.8 MAG 8.99,9.19 SP A2
HO 166 AB: 508; 667x: Snowman / overlapping disks at 667x & 1067x. Cleaner view at 667x & I can tell which one is A and which is B, and their orientation to other stars. Discovered 1886 at 0.4" it has a 79.29 year period, and I should be able to detect a quarter turn in the next 15 years and it will widen slightly.
21H 43M 54.25S +27° 50' 48.8" P.A. 250.7 SEP 0.218" MAG 8.36,8.25 SP F6V DIST. 95.15 PC (310.38 L.Y.)
A 299 AB: 508; 533x: Quite difficult given the B's faintness, close split ~1", ~2 delta mag. Discovered 1901 at 0.8" at Lick, so it's easier now.
21H 43M 31.64S +27° 20' 37.3" P.A. 66 SEP 1.1 MAG 9.95,10.47 SP G0
BU 692 AB: 508; 333x: V201 Peg. A is a bright light orange, B much fainter, blue, but an easy wide ~3". Discovered in 1878 at 2.48" with the Dearborn 18.5-inch.
21H 50M 05.37S +31° 50' 52.4" P.A. 10 SEP 2.9 MAG 7.47,11.03 SP K0 DIST. 181.16 PC (590.94 L.Y.)
HO 171 AB; 508; 333x: Lovely near equal white stars, well split.
21H 52M 08.95S +27° 48' 02.2" P.A. 342 SEP 0.8 MAG 9.36,9.50 SP A3 DIST. 512.82 PC (1672.82 L.Y.)
HO 609 AB: 508; 333x: Very light orange stars, ~1 delta mag, <3"
21H 55M 12.36S +29° 43' 33.1" P.A. 356 SEP 3.3 MAG 12.00,11.90
A 1226 AB: 508; 1067x: Olive shape at 667x & 1067x, best I can see. It's a physical pair but it won't make an appreciable change in its 120.4 year period in my time.
21H 57M 17.70S +32° 40' 32.4" P.A. 355.8 SEP 0.213" MAG 9.29,9.90 SP A3 DIST. 1063.83 PC (3470.21 L.Y.)
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