Zeeman Measures of Four Double-Lined Peculiar a Stars
Abstract
Zeeman measures of four Ap stars which are double-lined spectroscopic binaries are presented. There is no evidence for a magnetic field larger than a few hundred gauss in any of the component stars. The absence of strong magnetic fields in these stars, all of the Mn type, is another fundamental difference between this type and the well-known periodic magnetic variables of the Si and Eu-Cr-Sr types. Other established differences concern the abundances of the light elements and the iron-peak group, and the rotational velocities. There may well be different explanations for the anomalous spectral appearance of the Mn stars and the other Ap stars. The components of one binary studied, 46 Dra, are strikingly dissimilar. Both components show the Hg ii line, but only the primary shows Mn ii lines. These elements must be overabundant to be spectroscopically observable.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 1970
- DOI:
- 10.1086/150495
- Bibcode:
- 1970ApJ...160.1077C