Acrux

Acrux [from the Bayer designation α Crucis], brightest star in the constellation Crux (Southern Cross); 1992 position R.A. 12 ^h 26.2 ^m , Dec. -63°04′. Its apparent magnitude 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 star , with components of spectral classes B1 and B3, each component itself being a spectroscopic binary. Its distance is about 370 light-years.

Alpha Crucis The brightest star in the constellation Crux, also called Acrux. It is a double star consisting of a B0.5 subgiant, magnitude 1.3, and a B1 dwarf, magnitude 1.7. To the naked eye they appear as a single star of magnitude 0.8. Alpha Crucis is 321 l.y. distant.

Crux (abbr. Cru, gen. Crucis) The smallest constellation of all, better known as the Southern Cross. Its distinctive cross-shape is marked by four stars: Alpha Crucis (Acrux); Beta Crucis (Becrux or Mimosa); Gamma Crucis (Gacrux); and the faintest of the four, Delta Crucis, magnitude 2.8. Mu Crucis is a wide double of magnitudes 4.0 and 5.2. NGC 4755 is a sparkling open cluster known as the Jewel Box or the Kappa Crucis Cluster. Crux lies in a rich part of the Milky Way, part of which is blotted out by the dark Coalsackg nebula.