Program: GN-2016A-Q-20

Nowadays it is widely accepted that main-sequence stars with giant planets are, on average, more metal-rich than stars without planets. However, the results for giant stars with planets (GWP) have been more controversial and the issue of the planet-metallicity correlation for these stars remains open. Moreover, the study of chemical abundances of other elements besides iron provides valuable information about the elements that might also have an important contribution to planet formation. However, this analysis has been carried out only occasionally on GWP. To address these issues consistently, we have started a program to determine homogeneous stellar parameters and chemical abundances of a large sample of evolved stars with and without planets. We recently presented the results for 223 stars, including 56 GWP which represent ~55% of the current number of GWP, constituting one of the largest samples of GWP uniformly analyzed so far (Jofré et al. 2015a). This proposal aims to observe with GRACES 30 GWP in order to reach ~84% of the present number of GWP, and hence to confirm (or rule out) several interesting trends previously found as well as to establish, in a robust way, the real behavior of metallicity in GWP.