Heavy Element Abundances in Giant Stars of 47 Tuc

Abstract

This research forms part of an investigation into heavy element abundances in Asymptotic Giant Branch (AGB) stars in various stellar environments. Seven giant stars in the southern globular cluster 47 Tuc have been observed using the Anglo-Australian Telescope. Abundances for five s- and r- process elements have been determined: the light s-process elements, Y and Zr; the heavy s-process elements, La and Nd; and the r-process element Eu. Mean enhancements in the light s-process, [ls/Fe], of ~+0.6 dex and heavy s-process elements, [hs/Fe], of ~+0.3 dex were determined for all the giant stars. There was no statistically significant difference between the abundances determined for the Red Giant Branch (RGB) and AGB stars in this study. The results for the RGB stars differ from those obtained by a number of previous studies. However, because of the similar abundance results obtained for the AGB and RGB stars in this study we believe this provides evidence for previous enrichment of the material from which these stars formed.

References in corpus (4)

• Abundances in Stars from the Red Giant Branch Tip to Near the Main Sequence Turn Off in M71: III. Abundance Ratios
• Blue Straggler Stars: a direct comparison of Star counts and population ratios in six Galactic Globular Clusters
• C and N Abundances in Stars At the Base of the Red Giant Branch in M15
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• The age of 47Tuc from self-consistent isochrone fits to colour-magnitude diagrams and the eclipsing member V69
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