24 Comae Berenices (Struve 1657)

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Observation Notes:

This widely spaced double in Coma Berenices is a real showpiece, particularly when seeing conditions are good. The primary is a deep yellow-orange in color with a rich blue secondary hovering to the west. The steadily shimmering diffraction rings made them look like colorful gemstones resting in their settings. I estimated a position angle of 280 degrees and a separation of 20 – 25 arc seconds. The values listed in the Washington Double Star Catalog from 1830 are 271 degrees and 20.3 arc seconds. I’m including a ‘frozen’ detail image in the sketch to convey what this effect looked like.

Subject 24 Comae Berenices (STF 1657)
Classification Double Star
Position (J2000) Coma Berenices [RA: 12:35:07.7 / Dec: +18:22:37]*
Position Angle* 271° (1830)
Separation* 20.3″ (1830)
Magnitudes* 5.2; 6.7
Spectral Types* K0; A3
Date/Time JAN 26, 2007 – 06:20 AM MST (JAN 26, 2007 – 13:20 UT)
Observing Loc. Flagstaff, AZ – Home
Instrument Orion SVP 6LT Reflector (150 mm dia./1200 mm F/L)
Eyepieces/Mag. 10 mm + 2X Barlow (240X)
Conditions Clear, calm, 18° F
Seeing 6/10 Pickering
Transparency NELM Mag ~5.8
References The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996); Visual Double Stars in Hipparcos (Dommanget+, 2000)

*Based on published data.

2 Replies to “24 Comae Berenices (Struve 1657)”

  1. Very nice sketch of a beautiful pair. A small mistake in the text: the separation is around 20 arcseconds, obviously not 20 arcminutes

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