Daily Archives: August 9, 2006

Discovery of Carbon/Oxygen-depleted Blue Straggler Stars in 47 Tuc…

47 Tucanae (NGC 104) :: New published paper

The Astrophysical Journal Letters
Volume 647, Number 1
(August 10 2006)

F. R. Ferraro, E. Sabbi, R. Gratton, G. Piotto, B. Lanzoni, E. Carretta, R. T. Rood, Alison Sills, F. Fusi Pecci, S. Moehler, G. Beccari, S. Lucatello, and N. Compagni
“Discovery of Carbon/Oxygen-depleted Blue Straggler Stars in 47 Tucanae: The Chemical Signature of a Mass Transfer Formation Process”

Page L53 [ http://www.journals.uchicago.edu/cgi-bin/resolve?ApJL20841 ]

We use high-resolution spectra obtained with the ESO Very Large Telescope to measure surface abundance patterns of 43 blue straggler stars (BSSs) in 47 Tuc. We discovered that a subpopulation of BSSs shows a significant depletion of carbon and oxygen with respect to the dominant population. This evidence would suggest the presence of CNO burning products on the BSS surface coming from a deeply peeled parent star, as expected in the case of a mass transfer process. This is the first detection of a chemical signature clearly pointing to a specific BSS formation process in a globular cluster.

Table of Contents of ApL Volume 647, Number 1: