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Acrux(ā`krəks) [from the Bayer designation α Crucis], brightest star in the constellation CruxCrux
[Lat.,=cross], small but brilliant southern constellation whose four most prominent members form a Latin cross, the famous Southern Cross. The long arm of the cross, terminating in the brightest member, Acrux (Alpha Crucis), points almost directly at the south celestial
..... Click the link for more information. (Southern Cross); 1992 position R.A. 12h26.2m, Dec. −63°04'. Its apparent magnitudemagnitude,
in astronomy, measure of the brightness of a star or other celestial object. The stars cataloged by Ptolemy (2d cent. A.D.), all visible with the unaided eye, were ranked on a brightness scale such that the brightest stars were of 1st magnitude and the dimmest stars
..... Click the link for more information. of 0.86 makes it one of the 20 brightest stars in the sky, although its location in the far southern sky prevents it from being seen by most observers in the United States. Acrux is a visual binary starbinary star
or binary system,
pair of stars that are held together by their mutual gravitational attraction and revolve about their common center of mass. In 1650 Riccioli made the first binary system discovery, that of the middle star in the Big Dipper's handle, Zeta
..... Click the link for more information. , with components of spectral classesspectral class,
in astronomy, a classification of the stars by their spectrum and luminosity. In 1885, E. C. Pickering began the first extensive attempt to classify the stars spectroscopically.
..... Click the link for more information. B1 and B3, each component itself being a spectroscopic binary. Its distance is about 370 light-years.
Acrux(ay -kruks) See Alpha Crucis.