A quest for the red companion in six cataclysmic binaries.
Abstract
Near-infrared CCD spectra of six cataclysmic binaries have been obtained in an attempt to detect their red dwarf components. Similar observations of M dwarfs yield a classification scheme, based on TiO bands, which can be used to describe the red dwarfs in cataclysmic binaries. Observations of AM Her while in its low state revealed a red dwarf of type M4(+) V and a distance of 80 pc. The red dwarf in DQ Her was detected in an observation centered on mid-eclipse. The red star in DQ Her has a spectral type of M3(+) V, a mass = 0.32 solar mass, and a radius = 0.45 solar radius. The red star in DQ Her does not lie on the main sequence; although its temperature is correct for its mass, the radius is 25% too large. A spectroscopic distance estimate of 400 pc to the DQ Her binary system was obtained; in four additional systems, the red dwarf defied detection. Lower limits to their distances are given.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- August 1981
- DOI:
- 10.1086/159105
- Bibcode:
- 1981ApJ...247..960Y
- Keywords:
-
- Companion Stars;
- Dwarf Stars;
- Infrared Spectra;
- Novae;
- Stellar Spectrophotometry;
- Charge Coupled Devices;
- Near Infrared Radiation;
- Stellar Magnitude;
- Stellar Mass Accretion;
- Titanium Oxides;
- Astronomy