Saturday, September 22, 2018

some hercules doubles

Thursday night had some pretty good seeing, for a change, 8/10, with transparency starting 4/5 the dropping 3/5 after midnight.  Quarter moon but I went for some doubles:

90 Her = BU 130: I wanted to reobserve this after CalStar.  I had several seconds of airy disk at 553x, and moments of stillness at 885x, though the diffraction was less stable; there was some marine haze developing.  I viewed both with and without an apodizing mask, at 553x and 885x.  The best I can say is I had a definite snowman or bulge to the disk, very subtle, but no split.  I thought maybe this was because the star had approached closer since 2009's measure of 1.6" -- but indeed it's not the case.  Whatever deformity I saw was not the secondary, which remains a faint star perhaps hidden by the diffraction disk.
17H 53M 18.03S +40° 00' 28.6" P.A. 110 SEP 1.6 MAG 5.28,8.76 SP K3III DIST. 108.46 PC (353.8 L.Y.)

STF 2282: Faint yellow white, 3", half delta mag. 553x.  [I need to try this again since the B star is also a pair, but only 0.2"]
18H 06M 30.47S +40° 21' 39.6" P.A. 81 SEP 2.6 MAG 7.93,9.43 SP A1V DIST. 512.82 PC (1672.82 L.Y.)

BU 1127: Very tough but a small point of a star resolved at the rim of the diffraction ring at both 553x & 885x, using kind of a partial averted vision.  [Aa,Ab is 0.7" but no B mag given...]
18H 02M 30.89S +44° 14' 02.6" P.A. 42 SEP 0.8 MAG 7.31,9.20 SP F5V DIST. 81.3 PC (265.2 L.Y.)

STF 3129: White and wide separation, 2 delta mag fainter orange B. 
18H 01M 07.16S +45° 21' 03.3" P.A. 168 SEP 30.7 MAG 7.59,10.64 SP B9 DIST. 132.28 PC (431.5 L.Y.)

HU 235: Very certain point sitting just outside the diffraction ring; brightens and sharpens with seeing.  2" 2-3 delta mag 553x.  [This is supposed to be a good analog of BU 130, and I did return to BU 130 after this but still did not see it.]
17H 57M 05.08S +45° 51' 21.4" P.A. 285 SEP 1.6 MAG 6.88,9.04 SP F7IV DIST. 70.03 PC (228.44 L.Y.)

STF 2242: Easy matched yellow pair, 3"
17H 51M 10.32S +44° 54' 28.0" P.A. 327 SEP 3.4 MAG 8.14,8.28 SP F0 DIST. 118.06 PC (385.11 L.Y.)

AC 15: Extremely faint B, just on diffraction ring, with seeing, both 553x & 885x.  1"
18H 07M 01.61S +30° 33' 42.7" P.A. 331.4 SEP 1.44 MAG 5.13,8.96 SP F7V DIST. 15.64 PC (51.02 L.Y.)

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