Saturday, July 27, 2019

brief session

I attempted to control the telescope from my laptop last night, but could not connect to the servocat.  Am spending the day installing various software etc. and will try again tonight.

The rear fan still causes vibration and elongated stars.  It's not clear whether the front fan helps the image at all, and is causing diffraction on at least the apodizing mask.  I will give it some time but may end up using it for cool-down only.

I viewed a few targets last night.  Seeing was poor at low elevations but not so bad, maybe 7/10, up high.  The 8" mask was giving perfect images, and even at 20" I had relatively clean airy disks of fainter stars -- so there is hope.  For certain the 8" mask makes the sky background darker, but at 20" even with the brighter background there are (as one should expect) significantly more stars to see.  That will come in handy when sky conditions permit.  But last night was a dewy and the marine haze interfered starting around 11pm.

Most at 333x and 8":

STF 2232: Dull white and dull orange, well separated, ~3 delta mag.  Nice disks!
17h 50m 15.00s +25° 17' 27.6" P.A. 140 sep 6.2 mag 6.71,8.85 Sp A1V dist. 147.49 pc (481.11 l.y.)

STF 2220: Pretty, bright canary yellow A and much fainter bluish B. Nice! [A-BC seen. Missed AC 7 BC which are near equal 0.6" -- if only I removed the mask!]
17h 46m 27.51s +27° 43' 14.3" P.A. 249 sep 35.5 mag 3.49,9.78 Sp G5IV+M3.5 dist. 8.31 pc (27.11 l.y.)

STF 2194: Orange and light blue, wide separation, ~2 delta mag. [AB]
17h 41m 05.50s +24° 30' 47.2" P.A. 7 sep 16.4 mag 6.51,9.28 Sp K1III dist. 161.81 pc (527.82 l.y.)

M13: At 20", 333x.  Looks like a face-on spiral galaxy with star clusters showing like bright stars.

STF 2101: Forgot to put the mask back on so this was at 20" initially.  Nice airy disk with a little seeing diffraction.  Orange-yellow stars well separated ~2 delta mag.
16h 45m 48.14s +35° 37' 50.5" P.A. 47 sep 4.1 mag 7.51,9.39 Sp F6V dist. 58.82 pc (191.87 l.y.)


STF 2104: White A and slightly blue B, well separated, 2 delta mag.
16h 48m 41.48s +35° 55' 19.3" P.A. 17 sep 5.7 mag 7.49,8.78 Sp F2 dist. 172.71 pc (563.38 l.y.)

STF 2320: Wide separation 1 delta mag.  Suspected a close in pair to A in the 20" but it disappeared in 8". [What I saw in the 20" was the actual pair!]
18h 27m 45.89s +24° 41' 50.8" P.A. 1 sep 0.9 mag 7.14,8.90 Sp B9V dist. 256.41 pc (836.41 l.y.)

STF 2315: Any number of stars around could be the pair; appears like a small loose open cluster. [Not seen; the pair is 0.6"]
18h 24m 58.46s +27° 23' 41.3" P.A. 115.3 sep 0.6 mag 6.57,7.77 Sp A0V+A4V dist. 117.51 pc (383.32 l.y.)
BU 1326: Is it a double-double? In fact one seems to have another extremely faint star ~4" distant in the 20" [The extremely faint star is the AB pair]
18h 26m 40.93s +26° 26' 57.2" P.A. 107 sep 5.5 mag 6.48,12.10 Sp B3V dist. 321.54 pc (1048.86 l.y.)

I could smell the moisture in the air at this point.  Jupiter and Saturn were mushy and so low as to be diffracted by my fence and bushes.

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