The Composition of RR Lyrae Stars: Start-line for the AGB

Abstract

This paper sumarizes research on abundances in RR Lyrae stars that one of us (GW) has been engaged in with various astronomers. In addition we report on preliminary analysis of the abundances of C, Si, S and Fe in 24 RR Lyrae stars. Our model atmosphere analysis, including NLTE effects, are based on the spectra of resolving power 30,000 obtained at the Apache Poing Observatory.