Two ambiguously classified Ap stars, HR 830 and 21 CVn, are studied. The observational data are compared with the data for normal stars α Del and α Lyr. The star HR 830 is classified as Ap of type Si based on the enhanced absorption in the Si lines and photometric variability in UBV. 21 CVn is classified as Ap Si based on weaker absorptions of helium, the variability of helium lines, photometric periodic variability and the properties of the UV spectrum. It is concluded that the photometric periodic variability is a good indicator of Ap-properties of rapidly rotating A and late B stars.
Bulletin of the Astronomical Institutes of Czechoslovakia
- Pub Date:
- September 1984