STAR-CLUSTERS OF THE LARGE MAGELLANIC CLOUD .3. CCD-PHOTOMETRY OF NGC 2164

We have studied the colour magnitude diagram and the main sequence luminosity function of the young globular cluster NGC 2164 in the Large Magellanic Cloud in order to discriminate among possible scenarios for the evolution of intermediate mass stars. To this purpose, we have obtained the BV CCD photometry of stars in the cluster and in a nearby field. Two main schemes of stellar evolution are tested, the classical models incorporating semiconvection during the Hecore burning phase (Lattanzio, 1989) and the models taking into account convective overshoot during both core H-and He-burning phases (Bressan et al., 1981; Bertelli et al., 1985, 1986). The chemical composition of the stellar content of NGC 2164 turns out to be Z = 0.004 and Y = 0.25. The age of the cluster is 2 x 10(8) yr for model with convective overshoot, and 7 x 10(7) for models with semiconvection. The comparison of the observational integrated luminosity function for the main sequence stars, normalized to the number of evolved stars, with the theoretical one indicates that models incorporating convective overshoot ought to be preferred.