Superfast Line Profile Variations in the Spectra of OBA Stars III: A0 Star ${\alpha }^2$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 (LPVs) in the spectrum a chemically peculiar A0Vp star ${\alpha }^2$CVn are investigated using the January 6, 2020 observations carried out with the 6-meter BTA telescope at Special Astrophysical observatory (SAO) of the Russian Academy of Sciences (RAS) equipped with the MSS spectrograph. Regular short-term periodic variations of the H${}_{\beta }$, Fe\,II, and Cr\,II lines were detected with periods ranging from $\sim$4 to $\sim$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 $\approx$600\,G, which is close to the value expected from the well-known magnetic field phase curve.

arXiv comment11 pages, 8 figures

References in corpus (6)

• The SCORPIO focal reducer
• A Volume Limited Survey of mCP Stars Within 100pc II: Rotational and Magnetic Properties
• A Volume-Limited Survey of mCP Stars Within 100pc I: Fundamental Parameters and Chemical Abundances
• Stokes $IQUV$ magnetic Doppler imaging of Ap stars - III. Next generation chemical abundance mapping of Alpha 2 CVn
• Short time scale spectral variability in the A0 supergiant HD92207 and the importance of line profile variations for the interpretation of FORS2 spectropolarimetric observations
• New X-ray observations of IQ Aurigae and alpha2 Canum Venaticorum - Probing the magnetically channelled wind shock model in A0p stars