PI: Jae-Woo Lee, Sejong University, email@example.com
Address: Astronomy Department, 98 Gunja, Gwangjin, Seoul 143-747, Korea
CoI: Bruce W. Carney, University of North Carolina
CoI: Jina Lee, Sejong University
Title: Chemical Self-Enrichment History of 47 Tuc (NGC 104)
Abstract: During the last few years, it becomes very clear that some Galactic globular clusters (GCs) contain multiple stellar populations (MSPs). In particular, the most massive GCs contain MSPs with an exception of 47 Tuc, the fifth most massive GC. In contrast to early studies suggesting that 47 Tuc is a chemically and radially inhomogeneous GC, it has long been considered a monometallic GC. Our new Ca uvby photometry of the cluster shows that 47 Tuc has very broad red giant branch and horizontal branch sequences, indicating that it may contain heterogeneous stellar populations similar to results from early studies of the cluster by others. We propose to undertake a pilot program to obtain moderately high-resolution spectra for >=100 red horizontal branch (RHB) stars to investigate chemical self-enrichment signatures imprinted by supernovae or asymptotic giant branch (AGB) stars.
National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360