The chemical composition of late-type supergiants. III - Carbon, nitrogen, and oxygen abundances for 19 G and K Ib stars

Abstract

view Abstract Citations (72) References (38) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The chemical composition of late-type supergiants. III. Carbon, nitrogen, and oxygen abundances for 19 G and K Ib stars. Luck, R. E. Abstract Through an analysis of high-resolution, high signal-to-noise data, carbon, nitrogen, and oxygen abundances are investigated in 19 G and K Ib stars. The final analysis yields abundances for 16 of these objects; the other three have to be eliminated due to heavy blending of [C I] with a previously undetected line of FeH. The derived abundances show that, relative to solar values, these stars are heavily deficient in carbon and enhanced in nitrogen, and that there is also a moderate oxygen deficiency. The internal accuracy of the abundances is shown to be about 0.2-0.3 dex. Precise interpretation of the derived abundances is difficult, as the initial abundance distribution among carbon, nitrogen, and oxygen is uncertain. Assuming reasonable initial values, comparison with evolutionary theory indicates that these objects have been more heavily processed than would be expected on the basis of present calculations. There is a tendency for lower carbon abundances to be associated with low 12C/13C ratios. Subject headings: stars: abundances stars: late-type stars: supergiants Publication: The Astrophysical Journal Pub Date: January 1978 DOI: 10.1086/155764 Bibcode: 1978ApJ...219..148L Keywords: Abundance; Carbon; Chemical Composition; G Stars; K Stars; Late Stars; Nitrogen; Oxygen; Supergiant Stars; Stellar Models; Tables (Data); Astrophysics; Element Abundances:Late-Type Supergiants full text sources ADS | data products SIMBAD (18) Related Materials (3) Part 1: 1977ApJ...212..743L Part 2: 1977ApJ...218..752L Part 4: 1982ApJ...256..177L