Metal Rich Stars in omega Centauri

Abstract

I present some preliminary results from a high-resolution spectroscopic observing campaign conducted with UVES at the ESO VLT, devoted to the study of the newly discovered, metal-rich red giant branch (RGB-a) in omega Centauri. In particular, I derive and discuss accurate abundances of iron-peak elements, alpha-elements and s-process elements. The main results discussed in this contribution are: (i) the RGB-a is the most metal-rich component of the RGB stellar mix in omega Cen, with [Fe/H]=-0.62+/-0.06; (ii) the RGB-a has a lower alpha-enhancement compared to the other red giants, possibly due to SNe type Ia pollution and (iii) the s-process elements overabundance of the RGB-a is similar to that of the other red giants in omega Cen, and unusually high for globular cluster stars, due to pollution by low mass AGB stars.

11 pages, 5 figures, contributed talk at the 4th Carnegie Symposium "Origin and Evolution of the Elements"