The star Gacrux lies in the Southern constellation of Crux and is its third brightest star. It is visible only in the southern hemisphere.
Facts about Gacrux
Gacrux is one of the 25 brightest stars in the firmament with an apparent magnitude of 1.59 mag. Furthermore Gacrux with spectral class M3.5 is a red giant and its distance to the Sun is about 90 light-years. Moreover, the star has 1500 times solar luminosity as well as 110 solar diameters. In addition, Gacrux is a binary star with its companion being a 6.4mag bright blue-white star of spectral class A3. Although the companion Gamma Crucis B is with about 400 light-years more than four times as far away as the main star from the sun, it can still be observed with prism binoculars. Moreover, Gacrux is losing mass due to a strong stellar wind and has already evolved from a main sequence B star to a red giant. Therefore today it is already in a phase beyond helium burning.