Hot subdwarfs in detached binary systems and thick-disk cataclysmic variables from the Palomar-Green survey

Abstract

view Abstract Citations (89) References (29) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Hot subdwarfs in detached binary systems and thick-disk cataclysmic variables from the Palomar-Green survey. Ferguson, D. H. ; Green, R. F. ; Liebert, J. Abstract A total of 19 stars from the Palomar Green (PG) survey which were found to show composite spectra, generally with a hot subdwarf primary and a cool main-sequence secondary star, are discussed. The primary components have Teff values between 27,000 and 38,000 K (Mv = +5 to +7) and log g = about 6.5, while the secondaries generally show spectral types G8 to K4.5; however, these ranges are undoubtedly limited by selection effects, and extremely helium-rich subdwarfs were excluded as well. Aproximately half of all the PG subdwarfs could be in undetected binaries. Only two thick-disk cataclysmic variables with predominantly absorption-line spectra were found in the PG survey, which provides strong evidence that this kind of cataclysmic variable is luminous and confined to the Galactic plane (Population I). On the other hand, a few of the detached binaries show evidence for spectroscopic variations. Those which are close enough for a significant reflection effect on the secondary star may be progenitors to cataclysmic variable systems. Publication: The Astrophysical Journal Pub Date: December 1984 DOI: 10.1086/162691 Bibcode: 1984ApJ...287..320F Keywords: Binary Stars; Cataclysmic Variables; Dwarf Novae; Stellar Spectra; Absorption Spectra; Iue; Peculiar Stars; Spectral Energy Distribution; Stellar Color; Ultraviolet Spectra; Visible Spectrum; Astronomy full text sources ADS | data products SIMBAD (29) MAST (1)