Gacrux (γ Cru / γ Crucis / Gamma Crucis) is the third brightest star in constellation Crux (the Southern Cross) and the one of the brightest stars in the nighttime sky.
Since Gamma Crucis is at roughly −60° declination, it is only visible south of the Tropic of Cancer and therefore didn't receive an ancient traditional name; "Gacrux" is simply a combination of the "Ga" in Gamma plus Crux.
Gamma Crucis is a binary star, 120 light years distant from Earth. The main star possesses an apparent magnitude of +1.6 and belongs to the spectral classification M3 III. The +6.4 magnitude companion star (spectral classification A3) is in an angle of 25" with a position angle of 128 degrees of the main star, and can be observed with binoculars.
