Mu Crucis, Latinized from μ Crucis, is the seventh-brightest star in the constellation Crux commonly known as the Southern Cross.
They lie about 370 light-years away, and both stars are likely physically attached.
It is a hot massive main sequence or subgiant star, over a thousand times as luminous as the sun.
Its apparent magnitude is 5.2 and it is a Be star, a star spinning so quickly that it has ejected a disc of material that creates emission lines in its spectrum.
The disc is inclined at 36° to our line of sight.