The atmosphere of supergiant star HD 7927 (F0 Ia): Fundamental parameters and chemical composition

The atmosphere of supergiant star HD 7927 (F0 Ia) is investigated by the method of atmospheric model. The effective temperature and surface gravity are determined by comparing the observed and theoretical values of photometrical indices [ \mathrm{c_1} ], Q, and equivalent widths of Balmer lines: \mathrm{T_eff} = 7350 ? 200 K; log g = 0:4 ? 0:2. The microturbulence parameter is evaluated as ?t = 7:5 ? 1 km/s, based on studies of Fe II lines. The chemical composition of the star is determined. In the atmosphere of HD 7927, the C turned out to be a deficit, N, and Na in excess, the other investigated elements practically display solar abundance.