ABSTRACT
The loss of energy by a star through radiation to its much cooler surroundings leads to gravitational contraction and raises the temperature of the core. A star can thus increase its internal temperature as a consequence of energy loss to its surrounding, earning itself a negative specific heat. Eventually, nuclear reactions cease and there is not enough internal thermal pressure to support hydrostatic equilibrium. The progenitors of the type Ib/c supernovae may be the Wolf–Rayet stars, which are O-type stars at a very late stage of evolution that exhibit broad emission lines of ionized helium and/or other heavier ionized species. The energetics of the fast radio bursts quickly led to the conclusion that they were associated with magnetars, a class of neutron stars with extreme surface magnetic fields of strength ~1014 G. White dwarfs are stellar remnants consisting of an exposed stellar core composed of carbon and oxygen nuclei and their associated electrons.
