Lithium in late-type giants. II. 31 M giants and supergiants.
Abstract
A spectrum-synthesis technique accounting for TiO line blanketing and extracting Li abundances was developed to compensate for the unresolved TiO line depression of the Li I 6707 A doublet in high-resolution, high-SNR spectra of 31 M giants and supergiants. Li abundances in a 25-star sample show a large scatter about a mean log epsilon(Li) value of about -0.2. A renewed discussion of Li abundances for G and K giants offers new evidence for Li abundance control by stellar mass, consistent with M giant data. Two stars, Alpha Ori and 119 Tau, show no detectable Li line, and it is suggested that this Li deficiency may result from mass loss at the pre-main sequence phase, or from internal mixing and nuclear processing leading to Li destruction.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- May 1982
- DOI:
- 10.1086/159896
- Bibcode:
- 1982ApJ...256..189L
- Keywords:
-
- Abundance;
- Late Stars;
- Line Spectra;
- Lithium;
- M Stars;
- Red Giant Stars;
- Supergiant Stars;
- Aluminum;
- G Stars;
- High Resolution;
- K Stars;
- Main Sequence Stars;
- Nuclear Reactions;
- Spectral Resolution;
- Spectrum Analysis;
- Stellar Evolution;
- Stellar Mass Ejection;
- Titanium Oxides;
- Astrophysics