Spectrum of the star BM Ori at minimum light

1562-6873

stars—structure and evolution

Springer Online Journal Archives 1860-2000

Physics

Abstract Two spectra of the star BM Ori were obtained with the 2.6-m Crimean Astrophysical Observatory telescope near its maximum eclipse phase. The light detector was a CCD array. The wavelength range 5305–5373 Å was chosen in such a way that it contained no strong primary lines. Optimum filtration of the spectra yielded a signal-to-noise ratio of ∼300. Eighteen secondary lines are seen in the spectrum. Atmospheric parameters of the secondary star were determined: T eff=5740 K and logg=3.0; the secondary was classified by these parameters as being of spectral type G2 III. The best agreement between observed and synthetic spectra is achieved for metallicity [M/H]=−0.5 and microturbulence ξt=0 km s−1. The projected rotational velocity is Vsini=60 km s−, in agreement with the synchronous velocity in the hypothesis that assumes a total eclipse by the secondary star. Atmospheric elemental abundances in the secondary are estimated. Nickel, chromium, and iron exhibit an underabundance of ∼1 dex.

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