Mass Dependence in Gravitational Collapse of Stellar Cores

The mass dependence of the behavior of a stellar core undergoing gravitational collapse is examined, using an improved equation of state and improved mean-free path for energy transfer by neutrinos and antineutrinos. Energy loss due to the escape of muon-type neutrinos is included. For [Formula: see text] and [Formula: see text] there is explosive mass ejection. A neutron-star remnant of [Formula: see text] is left in the [Formula: see text] case, while in the [Formula: see text] case the remnant mass is [Formula: see text]. Upon cooling, the latter remnant may not be able to remain stable because of general relativistic effects. For [Formula: see text] and [Formula: see text] the models were too opaque to electron-type neutrinos to eject matter. In both cases they cooled by copious muon-type neutrino emission (to which they were transparent) and developed dense [Formula: see text] central regions in which general relativistic effects became important. It appears that highly evolved stars with [Formula: see text] may not be able to avoid the Schwarzschild singularity of general relativity.