The binary nature of the barium stars. II - Velocities, binary frequency, and preliminary orbits
1983; IOP Publishing; Volume: 268; Linguagem: Inglês
10.1086/160951
ISSN1538-4357
Autores Tópico(s)Astronomy and Astrophysical Research
Resumoview Abstract Citations (214) References (31) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The binary nature of the barium stars. II. Velocities, binary frequency, and preliminary orbits. McClure, R. D. Abstract A series of radial velocity observations has been obtained over the last 3 years of a sample of 20 Ba II stars. Seventeen of these (85%) are found to show long-term velocity variations ranging in amplitude from a few to tens of km s-1. Thus it seems likely that all Ba II stars are binary systems. An additional Ba ii star in the open cluster NGC 2420 is also found to have a variable velocity. Orbits for seven Ba II stars indicate low-mass companions, compatible with their being white dwarfs. Separations are large, about 2 AU on average. The peculiar abundances are not explained, but the fact remains that multiplicity must bear a causal relationship to these peculiarities. Publication: The Astrophysical Journal Pub Date: May 1983 DOI: 10.1086/160951 Bibcode: 1983ApJ...268..264M Keywords: Abundance; Barium; Binary Stars; Orbital Elements; Radial Velocity; Stellar Evolution; Companion Stars; Ephemerides; Giant Stars; Standard Deviation; Stellar Mass; White Dwarf Stars; Astronomy full text sources ADS | data products SIMBAD (76)
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