THE PRELIMINARY RESULTS OF INVESTIGATION OF ENIGMATIC STAR β LYRAE

Abstract

The results of preliminary spectral investigations of enigmatic star β Lyr have been presented. Spectral observations of this star were performed at Cassegrain focus of 2-m telescope of Shamakhy Astrophysical Observatory (ShAO) named after N.Tusi of Azerbaijan National Academy of Sciences, by using fiber-echelle spectrograph ShaFES with the CCD camera 4K×4K pixels, cooled by liquid nitrogen. Spectral resolution and wavelengths region are 56 000 and λλ3700-8500 ÅÅcorrespondingly. Here we presented mainly the results of spectral investigations of spectral lines Hα and HeI 6678. The line Hα is double-peaked emission. This line consists of "broad" and "narrow" emission components and with absorption feature that is always blue shifted. The spectral parameters (radial velocity, equivalent widths etc.) of emission components of lines Hα and HeI 6678 have been determined and character of the variability of these components was investigated. By measuring radial velocities of lines SiII λλ 6347 and MgII4481 the radial velocity curve of bright giant component (primary) was derived. The orbital period of β Lyr undergoes change because high mass loss rate of bright giant component. The period increases by ∼19 s per year. We determined the period of β Lyr corresponding to our observation season as 12.941428 days.