ELEMENTAL ABUNDANCE ANALYSES WITH DAO SPECTROGRAMS .14. THE DOUBLE-LINED SPECTROSCOPIC BINARY-112 HERCULIS

We have extensively studied both components of the double-lined spectr oscopic binary 112 Her using photographic region high-resolution Retic on spectra obtained at the Dominion Astrophysical Observatory. The orb ital radial-velocity curves for both stars have been used to derive mo re accurate orbital elements and a mass ratio of 1.98. We have employe d both fine-analysis and spectrum-synthesis techniques. 112 Her A is a n HgMn star with large He and Mg deficiencies, and a large iron overab undance. Its chemical composition is similar to that of HR 7664, anoth er hot HgMn star with a large Fe overabundance, but its Mn abundance f alls below the envelope of abundance versus temperature defined by mos t class members. 112 Her B exhibits a pattern of derived abundances si milar to the Am and partially similar to the cool rapidly oscillating Ap stars. Its photospheric elemental abundances are very similar to th ose of HR 4072 B and chi Lup B, which also have HgMn-star primaries.