The chemical composition and binarity of beta Crateris

A detailed abundance analysis of the bright A-type star betaCrt is presented. It is found that most of the abundances are essentially solar, indicating that the star is not a hot Am star. The only prominent anomalies are an underabundance of Al and overabundances of S, Sr and Ba. The barium overabundance is the most prominent and has important implications for the past history of this supposed binary system. The presence of the ROSAT-discovered white dwarf companion could indicate that the A-type star may have accreted material from the white dwarf progenitor. There are indications in the literature that the system is a relatively short-period binary. However, the radial velocity measurements presented in this paper show no apparent velocity changes, and do not support this hypothesis. It may be that the system is a wide long-period binary, or not even physically associated. Additional radial velocity measurements are required to investigate the orbit of this system.