ROTATING STARS - THE ANGULAR-MOMENTUM CONSTRAINTS

An important parameter to be considered in stellar evolution is the ratio cJ/GM2, where J is the angular momentum of a star and M is its total mass. This is a pure number which must be less-than-or-equal-to 1 for a neutron star or a black hole, but can take values much larger than one in a star at its birth. In this note we investigate the values of that ratio predicted by the numerical models of a stellar object during protostellar contraction as well as at the neutron star phase. In the latter case we consider relativistic models of slowly and fast rotating configurations.