Discovery of a X bootis like abundance pattern in the pulsating algol-type system RZ cassiopeiae

Abstract

The abundances of eight elements (C through Fe) were determined in the primary star of the short-period Algol-type binary RZ Cas relative to the A3 V spectroscopic standard star α PsA. Definite under-abundances (by -0.45dex or more) of Mg, Si, Ti, Cr, and Fe were established. On the other hand, light elements C and 0 show solar abundances, and Ca is slightly under-abundant (∼ -0.3 dex). This abundance pattern demonstrates that RZ Cas shows a characteristic of mild λ Boo-type stars. This finding raises a question on the physical relations between the metallicity (abundance anomaly), the pulsational characteristics, and the mass accretion processes. © 2006. Astronomical Society of Japan.