Oxygen-Sodium Anticorrelation in Fleld RR Lyr-Type Stars

摘要

We have performed analysis of a large amount of the fields RR Lyr type stars spectra with the aim to derive NLTE oxygen and sodium abundances in our program stars. Fundamental parameters (T_eff, log g, V_t) and metallicity were found using the method of the fitting between synthetic and observed spectra using the SME program which was developed by N. Piskunov and J. A. Valenti. As a result of this analysis anticorrelation between oxygen (O/H) and sodium (Na/H) abundances was found.