Peculiar Abundances of the Cool Carbon Star HE 1104-0957
Abstract
We present, for the first time, a detailed abundance analysis of the carbon star HE 1104‑0957 based on high resolution (R ≃ 50 000) spectra. Our analysis shows that the object is an extremely metal-poor star with [Fe/H] ≃ ‑2.96. We find that the object shows enhancement of carbon with [C/Fe] ≃ 1.82. However, it does not fall into any of the sub-groups of carbon-enhanced metal-poor (CEMP) stars based on the characteristic elemental abundance ratios used for the classification of various CEMP sub-groups. HE 1104‑0957 is also found to exhibit an enhancement of oxygen and nitrogen with [O/Fe], and [N/Fe] ≃ 1.54, and 2.54 respectively. In HE 1104‑0957, α-elements are found to be slightly enhanced with [α/Fe] ≃ 0.46. Fe-peak elements are also moderately enhanced in HE 1104‑0957 with a value 0.63 with respect to Fe. Our analysis shows that HE 1104‑0957 exhibits enhancement of neutron-capture elements, particularly r-process elements. The low-resolution spectra of this object shows the spectral features characteristics of a typical C-R star. However, we find that the surface chemical compositions of this object is contradictory to that expected for a C-R star. It requires a detailed analysis to better understand the abundance anomalies exhibited by this object.
- Publication:
-
Bulletin de la Societe Royale des Sciences de Liege
- Pub Date:
- June 2024
- DOI:
- arXiv:
- arXiv:2312.01769
- Bibcode:
- 2024BSRSL..93..445P
- Keywords:
-
- Metal-poor stars;
- Abundances;
- Chemically peculiar;
- Nucleosynthesis;
- Astrophysics - Solar and Stellar Astrophysics;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- Accepted for publication in Bulletin de la Soci\'et\'e Royale des Sciences de Li\`ege (BSRSL)