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)|
|Position (J2000)||Coma Berenices [RA: 12:35:07.7 / Dec: +18:22:37]*|
|Position Angle*||271Â° (1830)|
|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, 18Â° F|
|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.