A Few Binary Star Puzzles for Roberto on the Occasion of His Birthday

Abstract

Radial velocity observations accumulated during the past 16 years are used to derive a preliminary orbit for the CEMP star CS 22881-036. The velocity amplitude is very small. No velocity variation is found for three additional CEMP stars observed over roughly the same time interval. Searches for companions of two CEMP double-lined spectroscopic binaries and of the RR Lyrae star TY Gruis are reviewed. A disparity between the period distribution of disk carbon-star binaries and that of their parent population of normal binaries can be attributed qualitatively to a decline in accreted mass with increasing binary separation. Finally, possible reasons for failure to find expected companions of CEMP stars are discussed.

12 pages, 5 figures, Gallino Birthday Workshop

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Cited by in corpus (8)

• A Search for Stars of Very Low Metal Abundance. VI. Detailed Abundances of 313 Metal-Poor Stars
• The s-Process in Low Metallicity Stars. II. Interpretation of High-Resolution Spectroscopic Observations with AGB models
• The Ubiquity of the Rapid Neutron-Capture Process
• s-Process in Low Metallicity Stars. III. Individual analysis of CEMP-s and CEMP-s/r with AGB models
• Cannibals in the thick disk: the young $\alpha -$rich stars as evolved blue stragglers
• RR Lyrae Atmospherics: Wrinkles Old and New. A Preview
• A New CEMP-s RR Lyrae Star
• Field Blue Stragglers and Related Mass Transfer Issues