Estimación de edades de 15 cúmulos estelares de la Nube Menor de Magallanes

Abstract

By using V and I images obtained with the “Very Large Telescope” (Chile) for 15 star clusters in the Small Magellanic Cloud (SMC), we estimated their ages from the δV parameter, which is defined as the difference between the visual magnitude of the horizontal branch (or “clump”) and the corresponding visual magnitude of the turn off. We first performed the PSF photometry and then built the colour-magnitude diagrams of the clusters wherein we measured δV . This parameter, expressed in magnitudes, was calibrated by Janes & Phelps (1994) as a function of age. The ages here estimated for the 15 clusters , together with the metallicities we had previously derived applying the CaII triplet technique, allowed us to reanalize the age-metallicity relationship in the SMC.