Hα and Hβ Profile Variations in the Spectra of Early Supergiants HD198478 and HD187982

Profile variations in the Ha and Hb lines in the spectra of the stars HD198478 and HD187982 are investigated from spectroscopic observations acquired in 2010-2011, 2013-2015 at the Cassegrain focus of the 2-m telescope at the Shamakhy Astrophysical Observatory. The spectral resolution is approximately 15000.

The emission and absorption components of the Ha profile are found to disappear on some observational days in the spectra of HD198478. It is suggested that the observational evidence for the non-stationary atmosphere of HD198478 can be associated in part with non-spherical stellar wind.

It has been revealed that absorption in the line of Ha has variable structure in the spectrum of the star HD187982 depending on the activity phase of the atmosphere. The profile of the line has normal P Cyg type in the active phase of the star atmosphere. The emission component in the red wing of the profile forms and disappears. It is supposed that such variations may be due to non-stationary and strong flow substance in the atmosphere of this star.