Alpha Crucis


Distance (Light Years) 321 ± 21
Apparent Magnitude 0.77
Color (B-V)-0.24

Names For This Star

The name Acrux is probably a coinage of the American astronomer, Elijah H. Burritt, who published several editions of an astronomical atlas between 1833 and 1856. There word is derived from the name of the constellation, Crux, and the Bayer designation of the star as alpha. The Greek alpha, of course, corresponds to the Roman "A".

Description of the Star

Acrux A is the primary component of an apparently three star system. A is a blue B0.5IV subgiant star, much larger and brighter than our sun. The Millenium Star Atlas lists the apparent magnitude of this component as 1.34.

The B component lies at about 4.1 arc sec away from the A component, which represents a distance of at least 400 AU, that is, more than 10 times the distance between the sun and planet Pluto.

The C component lies about 90 arc sec away from A. This blue star is a B0.5IV subgiant of apparent magnitude 4.86.

Burnham lists Acrux as the fourteenth brightest star in the sky.

Other Designations For This Star

Hipparcos Identifier (HIP Number)


Harvard Revised (HR Number)


Henry Draper Catalog (HD Number)


Bonner Durchmusterung (BD Number)

CP-62 2745
Smithsonian Astrophysical
Observatory compendium (SAO Number)

Fundamental Katalog (FK5 Number)



Copyright © 1998 - 2010 by Arnold V. Lesikar,
Professor Emeritus
Dept. of Physics, Astronomy, and Engineering Science,
St. Cloud State University,St. Cloud, MN 56301-4498

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