Chemical Abundances of RR Lyrae Type C Star AS162158

We report the first extensive model atmosphere and detailed chemical abundance study of eight RR Lyrae variable stars of c subclass throughout their pulsation cycles. Atmospheric parameters effective temperature, surface gravity, microturbulent velocity, and metallicity have been derived. Spectra for this abundace analysis have been obtained with the echelle spectrograph of 100-inch du Pont telescope at Las Campanas Observatory. We have found metallicities and element abundance ratios to be constant within observational uncertainties at all phases of all stars. Moreover, the $\alpha$-element and Fe-group abundance ratios with respect to iron are consistent with other horizontal-branch members (RRab, blue and red non-variables). The [Fe/H] values of these eight RRc stars have been used to anchor the metallicity scale of a much larger sample of RRc stars obtained with low S/N "snapshot" spectra.