Small-Scale Variability in the Spectrum of Vega

Abstract

The results of observations of small-scale variations in the hydrogen Balmer lines in the atmosphere of Vega are presented. The spectral observations are performed with a low-resolution spectrograph (R ~ 600) installed in the Main Astronomical Observatory of the National Academy of Sciences of Ukraine. The spectra are obtained with a second-order time resolution. Variability has been detected in the hydrogen lines H_β, H_γ, H_δ, which can be interpreted as nonradial pulsations. The characteristic time of the observed variations ranges from 300 to 1200 s. The horizontal scale of the oscillating elements is approximately 800 mm, which is comparable to the solar radius. The radial velocity of the variations is approximately 36 km/s.