Do neutron stars have an ergosphere? Ergospheres are a property of black holes, and do neutron stars have it? If yes, why seldom article mentions that; if no, why can't neutron stars have this ergosphere component?
Neutron stars are generally not compact enough to have an ergosphere. Typically, the radius of a neutron star is several times the Schwarzschild radius corresponding to its mass. The ergosphere however starts at the Schwarzschild radius.