A

David

Darling

Menkalinan (Beta Aurigae)

Beta Aurigae

Menkalinan (Beta Aurigae) is the third brightest star in the constellation Auriga. Its Arabic name (also written as Menkarlina) means "the shoulder of the rein-holder." Menkalinan lies just 0.5 arc-minute away from the solstitial colure, the great circle in the sky that passes through both celestial poles and the summer and winter solstices. Menkalinan is a binary system consisting of two almost identical subgiant A stars in a tight orbit that, every 3.96 days, results in a partial eclipse of one star by the other by about a tenth of a magnitude. The twins, each about 48 times more luminous than the Sun, are separated by only about one-fifth the distance between the Sun and Mercury. So close are they, that they distort each other into an ellipsoidal shape through mutual tides. A faint red dwarf, well below naked-eye visibility, appears to orbit the pair at least 330 AU away.

 

visual magnitude 1.90
absolute magnitude -0.11
spectral type A2V
surface temperature 9,200 K
luminosity 95 Lsun
distance 82 light-years
position R.A. 05h 59m 32s,
Dec: +44° 56' 51"