Stars whose mass is 1.5-3 times more than the Sun will not be able in the end to stop his grip on the stage of the white dwarf. Powerful gravitational force will shrink them to the density at which happens "neutralization" substances: interaction of electrons and protons will lead to the fact that almost all mass stars will be enclosed in a neutron. Formed neutron star. The most massive stars can contact neutron, after they explode as supernovae.

The concept of neutron stars is not new: the first assumption about the possibility of their existence was made by talented astronomers Fritz Zwicky and Walter Barda from California in 1934. (somewhat earlier, in 1932. the possibility of the existence of neutron stars was predicted famous Soviet scientist L. D. Landau.) In the late 30-ies it became a subject of researches of other American scientists Oppenheimer and Volkova. The interest of these physicists to this problem was caused by the desire to define the final stage of evolution of massive cgi - rising stars. As the role and importance of the supernova was discovered at about the same time, it has been suggested that the neutron star may be the remnant of a supernova explosion. Unfortunately, with the outbreak of the second world war, the attention of scientists switched to military needs and the detailed study of these new and highly mysterious objects were suspended. Then, in the 50-ies, the study of neutron stars resumed theoretically, to determine whether they have the attitude to the problem of birth of the chemical elements in the Central areas of the stars. Neutron stars are the only astrophysical object, the existence and properties which have been predicted long before they are opened.

In the early 60-ies of the discovery of cosmic x-ray sources are very encouraged by those who considered the neutron star as possible sources of celestial x-ray radiation. By the end of 1967. discovered a new class of celestial objects - pulsars, which has led scientists to confusion. This discovery was the most important event in studying neutron stars, as it has once again raised the question of the origin of cosmic x-rays. Speaking of neutron stars, be aware that their physical characteristics are installed in theory and very hypothetical, because the physical conditions in these bodies, may not be reproduced in laboratory experiments. Critical properties of neutron stars exert a gravitational force. According to various estimates, the diameters of neutron stars are 10-200 km. And insignificant on space concepts volume "full" such quantity of a substance can be a heavenly body, like the Sun, with a diameter of about 1.5 million km and mass almost a third of a million times heavier than the Earth! The natural consequence of this matter concentration is extremely high density of a neutron star. In fact, it is so dense, that may even be hard. The gravity of the neutron star is so great that a man weighed down there about a million tons. The calculations show that the neutron star is strongly magnetized. According to estimates, the magnetic field of a neutron star can reach 1 mln. million Gauss, then how on Earth it is 1 Gauss. The radius of the neutron star is taken about 15 km, and weight - about 0.6 - 0.7 mass of the Sun. The outer layer is a model consisting of a rarefied electronic and nuclear plasma, which permeated the powerful magnetic field of the star. It is here that arise radio signals that are the hallmark of pulsars. Ultra-fast charged particles moving along the spiral along the magnetic field lines, give rise to different kinds of radiation. In some cases, there is radiation in the radio band of the electromagnetic spectrum, in the other - radiation at high frequencies. Almost immediately under the magnetosphere of the substance density reaches 1 t/cm3, 100 000 times the density of iron.

Following the outer layer has the characteristics of metal. This layer "superhard" substances in crystalline form. Crystals consist of atoms with atomic mass 26 - 39 and 58 - 133. These crystals are extremely small: to cover a distance of 1 cm, it is necessary to build in a line of about 10 billion crystals. Density in this layer more than 1 million times higher than in the outer, or otherwise, 400 billion times the density of iron. Moving on to the center of the star, we enter the third layer. It includes the area of heavy nuclei type of cadmium, but also rich in neutrons and electrons. The density of the third layer 1,000 times more than the previous one. Deeper penetrating into a neutron star, we reach the fourth layer, the density increases only slightly, by about five times. However, if the density of the kernel can no longer maintain their physical integrity: they break down into neutrons, protons and electrons. A large part of the substance is in the form of neutrons. For each electron and proton have 8 neutrons. This layer is, in essence, can be regarded as a neutron liquid "contaminated" electrons and protons. Below this layer is the core of a neutron star. Here the density of approximately 1.5 times more than in the overlying layer. Nevertheless, even such a small increase in density leads to the fact that the particles in the nucleus are moving much faster than in any other layer. The kinetic energy of motion of the neutron, mixed with a small number of protons and electrons, so great that constantly happen inelastic collisions of the particles. In the process of collision are born all known in nuclear physics, particles and resonances, of which there are more than a thousand. In all probability, there are a large number of not yet known particles. Temperature of neutron stars is relatively high. This is to be expected, considering as they arise. For the first 10 - 100 thousand years of existence, the stars, the core temperature is reduced to a few hundred million degrees. Then comes a new phase, when the core temperature of the star is slowly reduced due to the emission of electromagnetic radiation.