EXPLOSION OF A LOW-MASS NEUTRON-STAR

The hydrogynamical disruption of a low-mass neutron star is investigated for the case when the stellar mass becomes smaller than the minimum value, M(min) almost-equal-to 0, 1M.. The final phase of the process is shown to proceed explosively, leading to an expansion of all the star, with kinetic energy of 4,8 MeV per nucleon. The results of calculations are virtually independent of the way in which the neutron star mass goes down below M(min) (mass exchange in a close binary stellar system, nucleon decay, or some effective mass loss due to a hypothetical decrease of gravitational constant). The neutron star disruption is followed by a short (0,01 - 0,1 s) burst of thermal hard X-rays and soft gamma-rays (kT=10-100 keV) with a subsequent much more prolonged tail of radiation induced by decays of long-lived radioactive nuclides. Some fraction of the explosion energy may be emmited in the form of neutrinos.