The chemical composition of HD 196944: a carbon and s-process rich, very metal-poor star
Abstract
An LTE abundance analysis of the post-AGB candidate star HD 196944 is presented based on high resolution, high S/N spectra. The radial velocity of HD 196944 is found to be -174 km s(-1) indicating that it belongs to the halo population. The spectroscopic analysis provides the atmospheric parameters T_eff = 5250 K, log g = 1.7 (cgs), xi_t = 1.9 km s(-1) corresponding to those for G2-5 (bright) giants. A low iron abundance, [Fe/H] = -2.45, is derived confirming the old, low mass nature of the star. With [C/Fe] = +1.4 and a mean s-process overabundance of [s/Fe] = +1.1 the peculiar atmospheric composition of HD 196944 is confirmed. Possible evolutionary stages of HD 196944, that can explain its atmospheric parameters and composition, are discussed. Based on observations carried out at the European Southern Observatory, La Silla, Chile
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- September 1998
- Bibcode:
- 1998A&A...337..216Z
- Keywords:
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- STARS: EVOLUTION;
- STARS: ABUNDANCES;
- STARS: CHEMICALLY PECULIAR;
- STARS: AGB AND POST-AGB;
- STARS: INDIVIDUAL: HD 196944