VARIATION OF THE Hα LINE PROFILE IN THE SPECTRUM OF THE SUPERGIANT STAR HD 207260 (A2 Iae)

We present the results of a detailed spectroscopic investigation of the supergiant HD 207260 (A2 Iae), based on high-resolution echelle spectra obtained in 2018 with the 2-meter telescope at the Shamakhi Astrophysical Observatory. The focus is on the variability of the Hα line, which exhibits a complex and variable profile, consisting of both an absorption and an emission component. The intensity of the emission component and its radial velocity were found to vary significantly across different epochs. These changes were accompanied by synchronous variations in the radial velocity of the absorption and in the equivalent width of the line. Such behavior suggests a dynamical origin for the emission component, possibly related to instabilities in the upper atmosphere or episodic mass loss processes. Fourier analysis of the radial velocity variations reveals with an approximate of 35–40 days. This periodicity is consistent with the presence of radial or non-radial pulsations, which may drive structured outflows in the upper layers of the stellar atmosphere. It is assumed that the change in the Hα line profile, the change in the radial velocity and the equivalent width of the absorption and emission components of the Hα line profile occur as a result of the interaction of the stellar atmosphere with the circumstellar envelope as a result of the pulsation of the star.