DQ Herculis: Weak Sister to HZ Herculis
Abstract
A model for DQ Her is studied in which a strongly magnetic degenerate dwarf accretes matter from its companion in a close binary system. It is found that the model can explain major photometric and spectroscopic features of the system, including (1) the relative (visual) luminosities of the degenerate dwarf, the disk, and the companion star; (2) the relative amplitude and pulse profile of the 71-sec periodicity; and (3) the high effective temperature and relatively low luminosity of the degenerate dwarf. It is predicted that the rotation period of the degenerate dwarf is 142-sec and that, consequently, (1) the polarization of the emitted radiation may rotate through 360 deg each 142 sec, and (2) it is likely that detailed photometric observations can distinguish, at some level, between alternate pulses. Finally, it is suggested that the magnetic field in DQ Her is an internal fossil field exposed by an earlier nova outburst.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- September 1974
- DOI:
- 10.1086/181608
- Bibcode:
- 1974ApJ...192L.129L
- Keywords:
-
- Astronomical Models;
- Binary Stars;
- Dwarf Stars;
- Magnetic Stars;
- Astronomical Photometry;
- Companion Stars;
- Novae;
- Polarized Radiation;
- Stellar Luminosity;
- Stellar Magnetic Fields;
- Stellar Spectra;
- Astrophysics