The fourth brightest star in the constellation → Canis Major.
It is a B1 → giant of magnitude 2.0 lying about 500
→ light-years away. Mirzam is one of the brightest of the
→ Beta Cephei variable stars.
From Ar. al-Mirzam (المرزم) "subordinate," which according to
the Persian astronomer Biruni (A.D. 973-1048) was a general name for a relatively
fainter star lying beside a much brighter one, in this case
→ Sirius. Some sources have related the name of this star to
Ar. al-Murzim (المرزم) "the roarer." They claim that this name refers
to the fact that the star is situated to the east of Sirius and thus "announces, heralds"
imminent rising of Sirius. However, this interpretation does not seem tenable since
the meaning "announcing" is far-fetched, and moreover the angular distance between
Sirius and Mirzam being small, they actually rise together.