NEUTRON-STAR MOMENTS OF INERTIA

An approximation for the moment of inertia of a neutron star in terms only of its mass and radius is presented, and insight into it is obtai ned by examining the behavior of the relativistic structural equations . The approximation is accurate to approximately 10% for a variety of nuclear equations of state, for all except very low mass stars. It is combined with information about the neutron-star crust to obtain a sim ple expression (again in terms only of mass and radius) for the fracti onal moment of inertia of the crust.