Wednesday, February 28, 2024

27 february 2024

All in all a frustrating night.  Seeing was predicted to be good but it was variable.  It was to be excellent after 1am but I didn't notice a big improvement so wrapped up at 12:30am.  Since I was on the 20-inch I dwelled on the "movement" list, a very challenging list of known binaries which would exhibit movement over the next 20 years.  The are nearly all <0.5", most <0.3".  I could not get good results, and my pointing accuracy was off.  

I spent most of the night though going after Procyon B.  My white whale.  It's supposed to be at 5" separation to the north, and now through 2026 is the prime time to go for it.  I made another occulting eyepiece using a 9mm orthoscopic, and this time I'm happy it has a crisp edge and doesn't flare, though there is one area where it presents a ghost image (but I check for it by rotating the eyepiece).  I looked long and hard with just the 9mm and with a 2x barlow, and checked all quadrants, and nothing.  A couple times I noticed a hard point within one of the spider vane spikes, but after waiting an hour did not see it move off the spike.  The occulting band (a strip of tin foil) has a slightly uneven part which I found useful in hiding the primary behind to show more than 90-degrees of sky -- but no sign of the star.  I hope for a better night.  Perhaps it was the transparency, causing the sky to be too bright to show the faint companion.  It didn't help there was a waning moon rising at around 10pm.

I observed, or tried to, a few items from the movement list, but the conditions didn't support it.  I observed a couple of them which are beyond detectability, only to put a marker in them to compare years from now when they are.

STF1223 AB: 508; 150x: Near equal bright white stars, well separated. -8% PRO, 551 AU WS, 2.4+2.4 Msol, divergent proper motion, it is not binary. 
08h 26m 47.08s +26° 56' 07.8" P.A. 218.00 sep 5.2 mag 6.16,6.21 Sp A3V+A6V dist. 84.53 pc (275.74 l.y.)

STF1171 AB: 508; 300x: Very delicate faint B, closely separated from bright light-yellow A. -18% PRO, and even though there is only 186 AU WS, it is not likely binary.
08h 01m 00.78s +23° 34' 59.2" P.A. 326.00 sep 2.1 mag 6.48,9.95 Sp K1III-IV dist. 87.95 pc (286.89 l.y.)

COU 384 AB: 508; 1200x: Single at all powers.  No parallax data for the companion.  SOC grade 3 orbit, it is now closing rapidly and not likely to be detectible until apastron in 2050.  40.43-year period.
09h 18m 16.92s +18° 46' 51.7" P.A. 56.00 sep 0.125" mag 8.20,8.30 Sp F0 dist. 135.87 pc (443.21 l.y.)
RST3603 AB: 508; 850x: Very barest of splits with seeing, which is stable only in fleeting moments.  No parallax data for the companion.  SOC grade 3 orbit, 99-year period, it is just coming off apastron and will tighten to undetectability by 2040. 
08h 43m 07.66s -12° 25' 19.0" P.A. 317.00 sep 0.353" mag 7.80,9.61 Sp F3/5IV dist. 110.13 pc (359.24 l.y.)
MTG 1 AB: 508; 1200x: Single all powers, will widen rapidly from now to 2030 apastron and should be splitable.  No Gaia data.  Worth an annual look.  16.19-year period, SOC grade 3 orbit.
07h 11m 11.44s +43° 29' 58.1" P.A. 190.00 sep 0.06" mag 9.80,9.90 Sp M6.5+M6.5
KUI  23 AB: 508; 1200x: Single all powers.  SOC grade 2 orbit, it is at periastron now but will rapidly widen to apastron in 2028 and should be splitable.  No Gaia data.
06h 04m 07.22s +23° 15' 49.1" P.A. 358.00 sep 0.093" mag 4.77,5.50 Sp G7III dist. 47.55 pc (155.11 l.y.)
COU 292 AB: 508; 1200x: Single all powers.  No Gaia data.  SOC grade 2 orbit, 25.02-year orbit, it will tighten and not be detectible again until 2045 apastron, and even then it will be ~0.185"
10h 26m 54.22s +19° 30' 44.9" P.A. 50.00 sep 0.173" mag 8.42,8.79 Sp F8 dist. 79.05 pc (257.86 l.y.)

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