English

Fundamental parameters of red giants in 47 Tucanae

Solar and Stellar Astrophysics 2013-01-15 v1

Abstract

In these proceedings we present initial results of a spectroscopic analysis of a small sample of evolved K-giants in the globular cluster 47 Tucanae. We derive the effective temperature, surface gravity and microturbulence of all targets using standard methods. Further we derive LTE abundances of [Fe/H] and [O/Fe] as well as the abundance of sodium, using NLTE corrections. We find a mean metallicity for the cluster of [Fe/H]=0.75±0.10=-0.75\pm0.10, in excellent agreement with several other studies. Also, we confirm the sodium-oxygen anticorrelation previously reported by a number of other authors. Finally, we see indications of the sodium enriched stars also being enriched in heavy magnesium isotopes.

Keywords

Cite

@article{arxiv.1301.2994,
  title  = {Fundamental parameters of red giants in 47 Tucanae},
  author = {A. O. Thygesen and L. Sbordone},
  journal= {arXiv preprint arXiv:1301.2994},
  year   = {2013}
}

Comments

4 pages, 4 figures, proceedings of "Reading the book of globular clusters with the lens of stellar evolution", Rome, Nov. 26-28, 2012, in Memorie della Societa' Astronomica Italiana Supplementi