Superfast Line Profile Variations in the Spectra of OBA Stars. III. A0 Star α2 Cvn, New Results

Abstract—This work is a continuation of the studies of the ultrafast variability of line profiles in the spectra of early-type stars. Line profile variations in the spectrum a chemically peculiar A0Vp star α2 CVn are investigated using the January 6, 2020 observations carried out with the 6-meter BTA telescope at SAO RAS equipped with the MSS spectrograph. Regular short-term periodic variations of the Hβ, FeII, and CrII lines were detected with periods ranging from 4 to 140 minutes. The magnetic field of the star was determined for all observations. The average measured longitudinal magnetic field component over the entire duration of observations is about 600 G, which is close to the value expected from the well-known magnetic field phase curve.