Ultraviolet and X-ray detection of the 56 Peg system (K0 IIp + WD).
Abstract
Both IUE short and long wavelength exposures of the 56 Peg system are discussed. This mild barium star has an X-ray luminosity of 3 x 10 to the 31st power ergs/1, comparable to the rapidly rotating RS CVn binary systems, yet lies in a region of the HR diagram where stellar X-rays are generally not observed. This cool, bright giant is not a rapid rotator and the key to understanding its emission lies in the recent discovery of its white dwarf companion. Accretion onto the white dwarf of approximately 0.1% of the stellar wind of the primary is sufficient to power an X-ray source of the observed luminosity. Reprocessing of the X-rays in the cool dense stellar wind explains the origin of the UV emission line spectrum, and may explain the time varying asymmetry of the Mg 2 kappa line profile that is observed. Graphs which show observed fluxes and wavelengths are discussed.
- Publication:
-
SAO Special Report
- Pub Date:
- February 1982
- Bibcode:
- 1982SAOSR.392B.125S
- Keywords:
-
- Accretion:Stellar Winds;
- Barium Stars:Binaries;
- Barium Stars:White Dwarfs;
- Binaries:UV Spectra;
- Binaries:X Rays;
- Astronomical Spectroscopy;
- Binary Stars;
- Giant Stars;
- Stellar Spectra;
- Ultraviolet Spectra;
- X Ray Spectra;
- Barium;
- Emission Spectra;
- Iue;
- Lyman Alpha Radiation;
- Stellar Coronas;
- Stellar Winds;
- Astronomy