36 Andromedae (Struve 73)

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Observation Notes:

This double emitted a warm yellow light and was closely spaced. Seeing was not great, so I had some trouble estimating the separation of the two stars. There was clearly a black gap between the two, and the best I could tell, the first diffraction ring seemed to bisect its companion’s diffraction disc. That led me to estimate a separation of 1.2 arc seconds. PA measurements using my astrometric eyepiece on these close, jumpy doubles is pretty tough too. I came up with 315 degrees. Values noted in Brian Workman’s Double Star Calculator for 2007.7 are 320.4 degrees and 1.03 arc seconds.

Subject 36 Andromedae (STF 73)
Classification Double Star
Position (J2000) Andromeda [RA: 00:54:58.1 / Dec: +23:37:41]*
Position Angle* 315° [my measurement]
320.4° [2007.7 B. Workman DS Calculator]
Separation* 1.2″ [my measurement]
1.03″ [2007.7 B. Workman DS Calculator]
Magnitudes* 6.1 / 6.7
Spectral Types* K1IV
Date/Time SEP 20, 2007 – 09:45 PM MST (SEP 21, 2007 – 04:45 UT)
Observing Loc. Flagstaff, AZ – Home
Instrument Orion SVP 6LT Reflector (150 mm dia./1200 mm F/L)
Eyepieces/Mag. 10 mm Sirius Plössl + 2X Barlow (240X)
12 Meade Astrometric EP + 2X Barlow (200X)
Conditions Breezy, 1st quarter moon, patchy cirrus
Seeing 5/10 Pickering
Transparency NELM Mag ~5.0
*References The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996); Catalogue of Stellar Spectral Classifications (Skiff, 2005); Starry Night Pro Plus 5.8