Carbon, nitrogen and oxygen abundances in main-sequence stars. II. 20F and G stars.
Abstract
High-resolution Reticon spectra of red and near-infrared C I, N I, and O I lines have been analyzed to determine C, N, and O abundances in a sample of 20 F and G main-sequence stars. Their iron abundances, which have been determined from analysis of additional Reticon spectra of red Fe I lines, cover the Fe/H range from -0.9 to 0.4. Sulfur abundances have also been obtained. It is found that the variations of the carbon and sulfur abundances closely follow those of iron. The oxygen abundance varies much more slowly than iron (O/Fe = 0.48 (+ or - 0.07) Fe/H). This result confirms an earlier conclusion that oxygen is overabundant in more metal-deficient stars. The behavior of the nitrogen abundance appears to be similar to that of iron (N/Fe = 0.0 + or - 0.2). However, the unavailability of nitrogen abundances for the most metal-deficient stars in the sample makes this result less certain than the results for the other elements. These results are discussed in the light of current theories of stellar nucleosynthesis of the elements.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- November 1981
- DOI:
- 10.1086/159371
- Bibcode:
- 1981ApJ...250..262C
- Keywords:
-
- Abundance;
- Carbon;
- F Stars;
- G Stars;
- Main Sequence Stars;
- Nitrogen;
- Nuclear Fusion;
- Oxygen;
- Stellar Spectra;
- Atmospheric Models;
- Spectrum Analysis;
- Stellar Evolution;
- Tables (Data);
- Astrophysics