AN INVESTIGATION ON H-R DIAGRAMS OF GLOBULAR CLUSTERS

The most characteristic features of H-R diagrams of blobular clusters are summarized with particular regard to the position and the extension of the horizontal branch. A comparison of observations with theory in the two cases of evolution with and without mass loss is then shortly given. A preliminary approach to the evolution of models with large mass fractions (q0) in the helium cores is presented. Inhomogeneous equilibrium models with double energy sources have been computed in a range of values of q0 and of the total mass referring to possible horizontal-branch stars. © 1969 D. Reidel Publishing Company.