Unlike the sun, whose density is such that it supports nuclear fusion that generates bright sunlight, Gliese 581 is a red dwarf, so-called because the star is small and dim.

• 与太阳不同，太阳密度太高，能够支持生成强烈太阳光的核聚变，而Gliese581是颗红矮星，之所以这么叫是因为这个恒星又小又暗。