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.
Ferraro F. R., Sabbi E., Gratton R., Piotto G., Lanzoni B., Carretta E., et al. (2006). Discovery of Carbon/Oxygen-depleted Blue Straggler Stars in 47 Tucanae: The Chemical Signature of a Mass Transfer Formation Process. THE ASTROPHYSICAL JOURNAL, 647, L53-L56 [10.1086/507327].
Discovery of Carbon/Oxygen-depleted Blue Straggler Stars in 47 Tucanae: The Chemical Signature of a Mass Transfer Formation Process
FERRARO, FRANCESCO ROSARIO;SABBI, ELENA;LANZONI, BARBARA;BECCARI, GIACOMO;
2006
Abstract
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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
