ON THE VARIATION OF ABSORPTION LINES IN THE SPECTRUM OF THE LATE SG STAR HD 199478
Keywords:
mStars, atmospheres- stars, mass-loss - stars, supergiants - stars, winds, outflows - stars, circumstellar matter - stars, Variability magnetic chemically peculiar starsAbstract
The results of long-term (2011-2014) spectral observations of the supergiant star HD 199478, performed on the 2 m ShAO telescope, are presented. In this work, we are analyzed the data of photospheric absorption lines HeI λ 4921, 5876 Å, Si II λ 6347, 6371 C, C II λ 6578, 6583 Å. A significant change in radial velocities (RV) and equivalent widths (EW) were found according to
the data of 2011 and 2014. According to the 2011 data, smooth contraction of the star with a characteristic time of dierent lines from 43 to 59 days was revealed, while the radius of the star is reduced about 15-18%. As we have shown earlier, simultaneously with the contraction of the star, the HVA effect is observed when a high-velocity shift on the blue wing of the Hα and Hβ lines
is detected. The 2014 data indicate a synchronous change in the photosphere
and the outer gas shell of the star. In general, photospheric lines show the
complex nature of variability in dierent lines.
