Photospheric Variability of the Late B-Supergiant HD 199478

The results of spectral studies of photospheric lines of the late B-supergiant HD 199478 (B8Iae) in the visual range are presented. Our results for the first time ever, have shown that the scale of temporal variations in photospheric lines is in good coincidence with the quasi-cyclic variability of the emission component of the line Halpha. The instability of the periodicity according to the data of different years complicates the obtaining of accurate information about the pulsation modes and astroseismic information, which is required to study the photospheric variability in BA supergiants. The scale of temporal variations of 40-50 days is typical for the full cycle of variations in hydrogen. Our data revealed that these time scales are in good agree with absorption lines too. The distribution of the velocity gradient along the line shows the existence mainly radial, and to a lesser level, non-radial pulsations. The question of the main reason for the activity in the stellar atmosphere remains open. Given the above, to explain the observed spectral variations, we tend to accept the concept of the appearance of inhomogeneity on the surface of the star. For the explanation of the observed results, apparently, the magnetic field can play a key role. Measurements of the longitudinal magnetic field BA type SGs show that the maximum value of the magnetic field strength for beta Ori is 130 G, and for the remaining BA SGs it is several gauss. However, spots can cause the inhomogeneity on the surface of the star, where the local magnetic field is much higher