THEORETICAL-MODELS FOR MASSIVE STARS IN YOUNG MAGELLANIC CLOUD STELLAR CLUSTERS

We extend previous evolutionary computations of intermediate-mass stars to the range of massive star models. The computations have been performed for a fine grid of metallicities covering the range 0.002 less-than-or-equal-to Z less-than-or-equal-to 0.02, i.e., for a range of metallicity which appears suitable for evolving stars in young Magellanic Clouds globular clusters. Selected stellar models up to 20 M. have been followed from the zero-age main sequence through both the H-burning and He-burning phases till the final exhaustion of central He. The assumptions affecting the theory of massive stars are discussed, producing evidences supporting the adopted evolutionary scenario. The correlation between the star metallicity and the occurrence of blue loops during the central He burning phase is discussed, showing how star metallicity can tune the red-to-blue number ratio of He burning supergiants.