A White Dwarf Companion to the Main-Sequence Star 4 O 1 Orionis and the Binary Hypothesis for the Origin of Peculiar Red Giants
Abstract
In the course of an investigation with the IUE satellite of the ultraviolet spectra of peculiar red giants, the authors have discovered a white dwarf companion to the MS star 4 ο1Ori. They discuss the reductions performed for the ο1Ori IUE observations, and compare these with field white dwarfs to derive parameters of the white dwarf and the luminosity of the primary. Upper detection limits are derived for hot degenerate companions to four other bright MS stars, HR 363, RS Cnc, ST Her, and OP Her. Combined with the ο1Ori observations, it is argued that the nondetections for these stars are consistent with the statistics of field giant binaries and that either mass-transfer effects are not responsible for the incipient S-star nature of the MS stars, if their abundance peculiarities are recent, or that the MS stars must be older than 106yr.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- April 1988
- DOI:
- 10.1086/166183
- Bibcode:
- 1988ApJ...327..214A
- Keywords:
-
- Binary Stars;
- Companion Stars;
- Peculiar Stars;
- Red Giant Stars;
- S Stars;
- Ultraviolet Spectra;
- White Dwarf Stars;
- Carbon Stars;
- Iue;
- M Stars;
- Orion Constellation;
- Stellar Luminosity;
- Stellar Spectra;
- Astrophysics;
- STARS: BINARIES;
- STARS: INDIVIDUAL CONSTELLATION NAME: 4 O 1 ORIONIS;
- STARS: S-TYPE;
- STARS: WHITE DWARFS;
- ULTRAVIOLET: SPECTRA