Espectroscopia em alta resolução de gigantes vermelhas no aglomerado aberto NGC 2539

Abstract

The study of open clusters allow us to understand the behavior and structure of the Milky Way, as well as the formation and evolution of the stars. In that sense, red giant stars in open clusters are the best target of analysis because they are the brightest objects. We have analysed high-resolution echelle spectra (FEROS) of ten red giant members of the open cluster NGC 2539 to explore its chemical composition. Based on the high-resolution spectra and standard LTE analysis, we have derived stellar parameters and abundance ratios for elements from Na to Nd. Our findings confirm that NGC 2539 have similar compositions to within the errors of measurements compared with local disc field and open clusters giants. We also classified two of the spectroscopic binary stars of our sample as ``Yellow Stragglers'', and confirmed the nature of their companions; and calculated, for the first time, the rotation velocities for all the stars of our sample, showing their values good agreement with those already determined for field giant stars.