Spectral features of RZ Psc, a cool star with Algol-like brightness minima

Abstract

We have determined the physical (Teff, logg, ζ) and kinematic (Vesini,Vr) parameters and abundances for 14 chemical elements in the atmosphere of the “antiflare” variable RZ Psc, using medium-resolution spectra obtained with the Coude spectrographs of the 6-m telescope of the Special Astrophysical Observatory and the Crimean Astrophysical Observatory 2.6-m Shain telescope. The chemical composition of the star is characterized by a slight metal deficiency; however, the iron and calcium abundances are consistent with the solar values within the errors. We also detected a peculiar dip (depression) of the continuum level near the Hα line. Assuming that this depression and the photospheric Hα line have independent origins, we calculated the hydrogen abundance X in the atmosphere of RZ Psc. The resulting value X=0.70 (of the solar value) implies a relative deficiency of hydrogen. Together with the spatial location of the star, these properties provide evidence that RZ Psc is an evolved star, most likely belonging to population II.