The name "Gliese 581" refers to the catalog number from the 1957 survey "Gliese Catalogue of Nearby Stars" of 965 stars located within 20 parsecs of the Earth. Other names of this star include "BD-07° 4003" (BD catalogue, first known publication) and "HO Librae" (variable star designation). It does not have an individual name such as "Sirius" or "Procyon". The star is a red dwarf with spectral type M3V, located 20.4 light-years away from Earth. It is located about two degrees north of Beta Librae, the brightest star in the Libra constellation. Its mass is estimated to be approximately a third that of the Sun, and it is the 89th closest known star system to the Sun.