The /sup 12/C//sup 13/C ratio in stellar atmospheres. VII. 38 giants and supergiants

Journal Article · Wed Dec 15 04:00:00 EST 1976 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/154876· OSTI ID:7312405

Tomkin, J; Luck, R E; Lambert, D L

The /sup 12/C//sup 13/C ratios of 38 G, K, and M giants and supergiants have been determined. Included are the four Hyades cluster giants ..gamma.. Tau, delta Tau, epsilon Tau, and theta/sup 1/ Tau (ratios 19, 23, 22, and 20, respectively); the primary of ..cap alpha.. Aur (ratio 27); the Ba star 16 Ser (ratio 33); and the KO II-III star 37 Com which has the low ratio of 3.4. We point out that, at all giant and supergiant luminosities, there are stars with /sup 12/C//sup 13/C ratios too low to be explained by models of the evolution of static single stars. We discuss the effects of mass loss, meridional mixing, mixing at the helium flash, and the presence of a low-mass companion; we suggest that these four effects offer adequate scope to account for the observed low /sup 12/C//sup 13/C ratios. (AIP)

• Research Organization: McDonald Observatory and Department of Astronomy, University of Texas, Austin
• OSTI ID: 7312405
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 210:3; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
CARBON 12
CARBON 13
CARBON ISOTOPES
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
GIANT STARS
ISOTOPE RATIO
ISOTOPES
LIGHT NUCLEI
MATHEMATICAL MODELS
NUCLEI
NUCLEOSYNTHESIS
STABLE ISOTOPES
STAR EVOLUTION
STAR MODELS
STARS
STELLAR ATMOSPHERES
SUPERGIANT STARS