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Aleena, Almeisan, Gamma Geminorum, 24 Geminorum

Proper NamesAlhena, Aleena, Almeisan
Bayer DesignationGamma Geminorum
Flamsteed Number24 Geminorum
HR (BSC)2421
Right Ascension6h 37m 43s
Declination+16° 23' 57"
Distance109 light years
34 parsecs
MagnitudeApparent: +1.9
Absolute: -0.6
Spectral ClassA0 White Subgiant
Optimum VisibilityJanuary
NotesAfter Castor and Pollux, Alhena is the third brightest of the stars of Gemini; in the sky, it falls approximately halfway between those two stars and red Betelgeuse in Orion, to the southwest. This is a binary system, in which the primary white subgiant is orbited by a yellow dwarf star.

Alhena B is a yellow dwarf star similar in many ways to the Sun. It orbits the main white subgiant Alhena A following a highly eccentric path taking nearly thirteen years to complete. Alhena A is seen here in the distance, though in fact the white star is the larger and more luminous of the binary pair.


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