A southern hemisphere bright star (α Crucis) of magnitude 0.77 lying at a distance of 321 → light-years. It is apparently made up of three components. The primary component, Acrux A, is a blue subgiant of apparent magnitude 1.34 and spectral type B0.5 IV. The B component lies at about 4.1 arcsec 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 arcsec away from A.
Acrux, from A, from Alpha, designating the brightest star of the constellation + crux, the constellation name. 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.
The Southern Cross. A small but brilliant → constellation in the southern hemisphere, at 12h 30m right ascension, 60° south declination. Also known as → Southern Cross. The constellation contains four bright stars so situated that they depict the extremities of a Latin cross. Abbreviation Cru; genitive Crucis.
L. crux "cross, gibbet" is a rendering of the Gk. stauros "an upright stake or pole," in the Vulgate, the Latin translation of the Bible attributed to Saint Jerome at the end of the fourth century A.D.
Calipâ, loanword from Aramean.
Fr.: bras Écu-Croix
A spiral arm of our Galaxy located between the Sagittarius Arm and the Norma Arm, though it is rather less prominent than either of these two better defined spiral arms. It originates relatively close to the Sun's present position in the Galaxy, and follows a sweeping arc of about 80,000 light years to the opposite side of the Galactic disk.