Rotational Velocities of AP Stars
Abstract
Projected rotational velocities were measured on coude' spectra for essentially all the northern bright Ap stars. Differences in these rotational velocities between subgroups are found to be marginal, except that Guthrie's discovery of a deficiency of very narrow-lined Si stars is confirmed. Ap stars have onequarter the mean projected rotational velocity of normal stars of the same types and luminosities, hut it is likely that a low rotatinnal velocity is an insufficient criterion to produce a peculiar spectrum. Ap stars cannot be explained simply by an aspect effect. A comparison of projected rotational velocities with equatorial rotational velocities computed from periods of variations in light, magnetic field, or spectrum leads to evidence for random orientations of rotational axes.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- August 1972
- DOI:
- 10.1086/151598
- Bibcode:
- 1972ApJ...175..779A