According to the modern, fusion leads over time to the enrichment of the internal areas of heavy elements in stars. In the process of fusion of heavy elements and education star contracts and the temperature at the center grows. (The effect of negative heat of gravitating matter nondegenerate.) If the mass of the star core is large enough (from 1.2 to 1.5 solar masses), the fusion process reaches its logical conclusion with the formation of nuclei of iron and nickel. Inside the shell begins to form a silicon iron core. This nucleus grows daily, and collapsing in less than 1 second, as soon as reaches chandrasekarovskogo limit. For the kernel, the limit ranges from 1.2 to 1.5 solar masses. Substance falls into the star, the repulsion of the electrons can not stop falling. The central nucleus is increasingly compressed, and at some point because of the pressure in the beginning to read the reaction neytronizatsii - protons begin to absorb electrons, turning into neutrons. This causes a rapid loss of energy, resulting flue neutrinos (the so-called. Neutrino cooling). The substance continues to accelerate, down and shrink, until beginning to affect not repulsion between the nucleons of atomic nuclei (protons, neutrons). Strictly speaking, the shrinkage occurs even more this limit: falling matter of inertia exceeds the balance due to the elasticity of Nucleons by 50% ( max pressure). The process of collapse of the central nucleus so fast that it is formed around a wave of dilution. Then followed the nucleus to the center of the star rushes and shell. Then compressed rubber ball pays back, and the shock wave goes into the outer layers of the star at speeds of 30000 to 50000 km / sec. External razletayutsya of stars in all directions, but exploded in the center of the field remains the compact neutron star or black hole. This phenomenon is called a type II supernova explosion. Explosions, these vary in power and other parameters, as well as exploding stars of different masses and different chemical composition. There is evidence that, in type II supernova explosion energy is allocated little more than an explosion when I type, as well as a proportional part of the energy absorbed by the shell, but perhaps it is not always the case.
In the described scenario, there are a number of uncertainties. In astronomical observations established that massive stars actually explode, resulting in expanding nebula, while the center remains a rapidly rotating neutron star emitting regular pulses of radio waves (the pulsar). But the theory shows that the shock wave reaching out to split the atoms in the nucleons (protons, neutrons). It should be wasting energy, resulting in a shock wave should pogasnut. But for some reason this does not happen: shock wave for a few seconds, reaches the surface of the nucleus, then - the surface of the star and blown off the substance. We consider several hypotheses for the different masses, but they do not seem convincing. Perhaps, in a state of maximum pressure, or in the interaction of the shock wave from the substance continued to fall due to enter any fundamentally new and unknown physical laws. Furthermore, in a supernova explosion with the formation of a black hole raises the following questions: why the substance after the explosion is not completely absorbed by the black hole, if there is a shock wave coming out and why it has not slowed down, and if there is something similar maximum ressure?