Stars in the spherical clusters

The population of spherical clusters (the old Galaxy objects) is considered on a popular level. The origin of spherical clusters, the process of star enrichment by heavy elements are explained. Presented are the photographs of spherical clusters of the Galaxy, of the Serpent and Berenices Hair constellations. The possible evolutions of spherical cluster stars in the Hertzsprung-RUssel diagram is discussed. Considered is the star lifetime in the main sequence. The branches of red giants, pulsating stars are given. Presented are the Hertzsprung-Russel diagrams for a spherical cluster, marked with a band of instability, and the diagram for M5 cluster in the Serpent constellation obtained from observations. Tracked is the evolution of spherical cluster stars up to the formation of pulsars, white dwarf stars, neutron stars and black holes