Fundamental parameters of red giants in 47 Tucanae

TL;DR

This study presents spectroscopic analysis of red giants in 47 Tucanae, determining their fundamental parameters and chemical abundances, confirming known abundance patterns and suggesting possible correlations with magnesium isotopes.

Contribution

First spectroscopic analysis of evolved K-giants in 47 Tucanae deriving fundamental parameters and chemical abundances with NLTE corrections, confirming and extending previous findings.

Findings

Mean metallicity [Fe/H] = -0.75 ± 0.10

Confirmation of sodium-oxygen anticorrelation

Indications of sodium enriched stars also enriched in heavy magnesium isotopes

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]$=-0.75\pm0.10$, 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.