2008BaltA..17..195K

Using the high resolution spectra obtained with the Nasmyth Echelle Spectrograph of the 6 m telescope the hydrogen-deficient single-line binary system KS Per is analyzed. The atmospheric parameters derived are: T_eff = 9500±300 K, logg = 2.0±0.5 and ξ_t=9.5±0.5 kms^–1. The hydrogen deficiency is H/He = 3x10^–5, the iron abundance is reduced by 0.8 dex, the nitrogen abundance is very high [N/Fe] = 1.4, but carbon and oxygen abundances are low. The star luminosity is log L/L_☉ = 3.3. A complex absorption and emission structure of the NaID doublet was revealed. We suggest that the emission component is formed in the circumbinary gaseous envelope. The early B-type less luminous companion influences the spectrum of the system for the wavelengths shorter than 180 nm.