вторник, 4 июля 2017 г.

Short time-scale variability in the spectrum of O-B hot stars

Main Astronomical Observatory of NAS of Ukraine, Akademika Zabolotnoho str., 27, 03680 Kyiv, Ukraine

We reported the first results of observations of short time-scale variability in the hydrogen Balmer lines and HeI lines  in the hot O-B stars (η UMa, ζ Ori). Spectral observations were carried out with low-resolution slitless spectrograph (R ~ 200) installed on the 60 cm Carl Zeiss telescope in the Andrushivka Observatory, Ukraine. Spectra were obtained with a time resolution in the sub-second and second range. It has been found that the hot stars shows rapid variations in the hydrogen lines Hβ, Hγ, Hδ, Hε, Hη and helium lines HeI(4472Å), HeI(5016Å) HeI(5876Å) as well as variations in the atmospheric oxygen lines. This can be interpreted that their pulsations are non-radial pulsations and strong stellar wind.