Light-element abundances in the weak G-band star HR 6766.
Abstract
Results are presented for a model-atmosphere analysis of iron-peak elements, the CNO group, and lithium in the weak G-band star HR 6766. Synthetic spectra are generated to derive the carbon, nitrogen, oxygen, and lithium abundances; the C-12/C-13 ratio is determined from a curve-of-growth analysis. An effective temperature of 4750 + or 100 K is estimated along with log g of 2.0 + or - 0.4 and a microturbulent velocity of 2.0 + or - 0.5 km/s. The overall metal abundance derived from these parameters is shown to indicate a marginally significant metal deficiency, and it is suggested that HR 6766 appears to be in most respects a normal late G or early K giant. An analysis of the carbon abundance based purely on the G band of CH reveals a very large underabundance of carbon. A C-12/C-13 ratio of about 4.1 is obtained, the results are compared with those for Epsilon Virginis, and the mass and luminosity of HR 6766 are discussed.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 1978
- DOI:
- 10.1086/156173
- Bibcode:
- 1978ApJ...222..585S
- Keywords:
-
- Abundance;
- Atomic Spectra;
- Light Elements;
- Stellar Atmospheres;
- Stellar Models;
- Stellar Spectra;
- Atmospheric Models;
- Carbon Isotopes;
- Emission Spectra;
- Line Spectra;
- Lithium;
- Nitrogen;
- Oxygen;
- Stellar Spectrophotometry;
- Astrophysics;
- Element Abundances:Weak-Line Stars