Nitrogen abundance in early B-stars. I. NLTE calculations for gamma Pegasi

Based on Kurucz (1992) grid of models the NLTE calculations of nitrogen abundance in gamma Peg atmosphere revealed a slight deficiency of this element comparably to solar value ([N/Hright ] ~ -0.3). Together with the recent result on carbon abundance in this star atmosphere ([C/Hright ] = -0.25; Korotin et al., 1998), the present determination shows that turbulent diffusion in massive main sequence stars (discussed by Maeder, 1987) and connected with it the appearance of the CN-processed material at the stellar surface can hardly be operating in gamma Peg. The list of N Ii lines that can be used for LTE calculation of nitrogen abundance in hot stars is also presented.