Atmospheric iron abundance in the primary component of υ Sgr

Based on the observed energy distribution and line spectrum of the primary component of the binary υ Sgr, we computed blanketed model atmospheres. The atmospheric iron abundance in the primary component of υ Sgr was derived from photographic and CCD spectra. Our analysis confirmed the previously inferred T _eff = 13500 ± 150 K and logg = 2.0 ± 0.5. The microturbulent velocity was found from spectral lines in different spectral ranges to be V _t = 8–12 km s^?1. We refined the mass fractions of light elements: 10^?4 for H, 0.91 for He, 0.013 for C, 0.049 for N, and 0.008 for O. The iron abundance was determined with a high accuracy from Fe I, Fe II, and Fe III lines in the spectral range 4000–7000 Å: log (N(Fe)/∑N _i ) = ?3.80±0.20.