HD 145206 : the first semibarium star with a main-sequence close companion ?

Abstract

A 12 A/mm photographic spectrum of the binary red giant HD 145206 revealed slightly enhanced s-process lines with respect to standard stars of the same temperature and luminosity. The spectrum closely resembles that of a Ba0.5 semibarium star (following the classification of Keenan and Pitts, 1980) used for comparison. The mass transfer scenario generally invoked in order to explain barium stars cannot apply to this system, as the semibarium star companion is not a white dwarf.