An intense extreme-ultraviolet source in Cetus.
Abstract
The detection of a second EUV (100-1000 A) probable white dwarf star with the EUV telescope aboard the Apollo Soyuz mission is reported. The positional error box includes Feige 24, a binary system consisting of a very blue white dwarf and a dMe star. A grid of LTE pure-hydrogen, high-surface-gravity model atmospheres, is used, in combination with the EUV data and optical spectrophotometry, to derive the stellar parameters, yielding an effective temperature of 60,000 K, a radius of 17,000 km at 100 pc, and a luminosity of 7(d/100 pc) squared solar luminosities. The Feige 24 models appear to rule out white dwarfs with pure hydrogen atmospheres if the interstellar helium abundance and ionization are not anomalous.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 1976
- DOI:
- 10.1086/182308
- Bibcode:
- 1976ApJ...210L..79M
- Keywords:
-
- Binary Stars;
- Far Ultraviolet Radiation;
- Hot Stars;
- Stellar Luminosity;
- Stellar Temperature;
- White Dwarf Stars;
- Apollo Soyuz Test Project;
- Interstellar Gas;
- Stellar Radiation;
- Stellar Spectra;
- Stellar Spectrophotometry;
- Astrophysics