Mu Crucis (DUN 126)

Observation Notes:

While enjoying the view from the summit of Haleakala on Maui, I was able to make a binocular observation of the wide double, Mu Crucis. This wide double was a nice binocular target and was only difficult to split when the wind was shaking my lightweight tripod. The primary was bright blue and the secondary appeared to be an elusive orange color. This must have been a contrast effect, since the secondary is a B5 star. This is as far south as I’ll be getting on a double star for a good long while: -57° declination is 2 degrees below the horizon in Flagstaff, and about ten degrees below a useful altitude from here.

Subject Mu Crucis (DUN 126)
Classification Double Star
Position (J2000) Crux [RA: 12:54:35.5 / Dec: -57:10:40]*
Position Angle* 17° (1826)
Separation* 34.9″ (1826)
Magnitudes* A: 4.03 / B: 5.17
Spectral Types* B3 / B5
Date/Time JUN 3, 2007 – 9:30 AM HADT (JUN 4, 2007 – 10:30 UT)
Observing Loc. Haleakala Summit, Maui, HI (10,000 ft.)
Instrument Oberwerk 15 x 70 Binoculars
Eyepieces/Mag. 15X
Conditions Clear, cool, Breezy
Transparency NELM Mag ~6.5
References The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996); Catalogue of Stellar Spectral Classifications (Skiff, 2005)

*Based on published data.