Discovery of Broad-Band Optical Circular Polarization in Alpha Leonis
Abstract
Variable broad-band optical circular polarization of amplitude 0.001 percent in the rapidly rotating, upper main-sequence star Alpha Leo. The variability does not appear to correlate with the suggested range of the rotation period of the star (11-22 hr), but it does occur on short time scales. When compared to observations of the known magnetic star Alpha exp 2 CVn, the magnitude of the observed circular polarization indicates an effective magnetic field on the order of 1 kG is present. The circular polarization exhibits sign reversals which suggest a dipolar geometry to the field, a characteristic of the fields of magnetic Ap stars.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- May 1989
- DOI:
- 10.1086/185440
- Bibcode:
- 1989ApJ...340L..65H
- Keywords:
-
- Circular Polarization;
- Magnetic Stars;
- Main Sequence Stars;
- Optical Polarization;
- Visible Spectrum;
- Spectral Line Width;
- Stellar Magnetic Fields;
- Stellar Rotation;
- Variable Stars;
- Astrophysics;
- POLARIZATION;
- STARS: INDIVIDUAL CONSTELLATION NAME: ALPHA LEONIS;
- STARS: MAGNETIC;
- STARS: VARIABLES