The Spectroscopic Binary Characteristics of the Mercury-Manganese Stars

Abstract

SummaryThe 80 confirmed and suspected mercury manganese stars identified prior to 1974 and north of declination -20° have been studied from 654 high dispersion spectrograms. (2.4 - 15 Å mm-1) for velocity and degree of peculiarity. The binary frequency based on velocity variability criteria alone appears to be a normal main sequence value of about 50%, and is probably independent of the degree of enhancement of the mercury and manganese lines. New spectroscopic orbital elements are given for six systems: α And, 2 Per, κ Cnc, φ Her, HR 6620 and 46 Dra. The Hg Mn spectrosopic binaries appear to be fairly normal in their orbital characteristics, except that periods less than 3 days are conspicuously absent; there is also weak evidence for more nearly circular orbits amongst the short period Hg Mn binaries than in comparable normal binaries.