Metalicidades y Velocidades Radiales precisas de Cúmulos Globulares pertenecientes al Bulbo de la Vía Láctea

M.C. PARISI; D. GEISLER; R. COHEN; F. MAURO; S. VILLANOVA; I. SAVIANNE

Malargüe

Congreso; 60 Reunión Anual de la Asociación Argentina de Astronomía; 2017

Observatorio Pierre Auger

We present preliminary results of the analysis of the radial velocities and metallicities of red giant stars of the globular cluster NGC 6642, belonging to the Milky Way bulge. The mentioned parameters have been determined from spectra in the Ca ii Triplet region, obtained with the instrument FORS2 on the Very Large Telescope (Chile). We found that stars with high probability of being members of the cluster, according to their radial velocities, belong to two groups of stars with a difference of 0.38 dex in their mean [Fe/H]. If this difference were verified, this would be a result of great relevance both in terms of the formation and evolution of these star systems, and the formation of the bulge of our Galaxy.