An Etymological Dictionary of Astronomy and Astrophysics

A → chemically peculiar star of late → B-types. The most distinctive features of HgMn stars are extreme atmospheric overabundance of Hg (up to 5 dex) and of Mn (up to 3 dex). The origin of abundance anomalies observed in late B-type stars with HgMn peculiarity is still poorly understood. More than two thirds of the HgMn stars are known to belong to spectroscopic binaries with a preference of orbital periods ranging from 3 to 20 days (Hurbig et al., 2012, arXiv:1208.2910).

See also: Hg, → mercury; Mn, → manganese; → star. mercury-manganese