THE CHEMICAL-COMPOSITION OF IK PEGASI

A detailed abundance analysis of the pulsating A-type star IK Peg A is presented. It is found that the Ca and Sc abundances are approximatel y solar and the Fe-group elements slightly enhanced, Hence, IK Peg A i s not a classical Am star, but the results are not inconsistent with i ts spectroscopic classification as a marginal Am star. The presence of a massive white dwarf companion (IK Peg B) indicates that the binary system has previously undergone a common envelope phase, Enhancements of Ba and Sr are found, which may be evidence of mass transfer from th e white dwarf progenitor during this common envelope phase. This, howe ver, is purely speculative, since the abundance anomalies may be expla ined by radiative diffusion processes operating in the atmosphere of I K Peg A, even though it is undergoing small-amplitude pulsations. It i s suggested that IK Peg A is a hot member of the F str lambda 4077 sta rs.