We present iron and \alpha element ( Mg , Ca , Ti ) abundances for a sample of 15 Red Giant Branch stars belonging to the main body of the Sagittarius dwarf Spheroidal galaxy .
Abundances have been obtained from spectra collected using the high resolution spectrograph FLAMES-UVES mounted at the VLT .
Stars of our sample have a mean metallicity of [ Fe/H ] =-0.41 \pm 0.20 with a metal poor tail extending to [ Fe/H ] =-1.52 .
The \alpha element abundance ratios are slightly subsolar for metallicities higher than [ Fe/H ] > \lower 4.558 pt \hbox { $ \kern - 10.7 pt { \sim } $ } -1 , suggesting a slow star formation rate .
The [ \alpha /Fe ] of stars having [ Fe/H ] < -1 are compatible to what observed in Milky Way stars of comparable metallicity .