Spectroscopy of Selected Pulsating Stars: the Anomalous Variable V351 CEP

The physical parameters: effective temperature Teff, surface gravity log g, microturbulent velocity t, abundances of 26 chemical elements, radial velocity Vr - were obtained for 5 phases of the variable star V351 Cep using CCD echelle spectra with spectral resolution R = 25000 in the region 5100-8800 Å. The chemical composition of V351 Cep coincides within the errors with the solar composition and, except for the CNO elements, it coincides with the chemical composition of the young supergiant Per. It is shown that the massive supergiant Per has an essential overabundance of N and deficiency of C, O in comparison with the solar abundances, which is in good agreement with evolutionary status of Per. At the same time, no considerable modifications of the CNO abundances for V351 Cep were found. It evidences for absence of dredge-up H-burning products to the surface of the star.

The luminosity of V351 Cep, MV = -3.m0, was obtained using the intensity of the infrared triplet OI (near 7774 Å). This value is not consistent with the luminosity obtained from the P-L relation.

The combination of the physical parameters of V351 Cep allows to classify V351 Cep as an anomalous cepheid.