The death of the star

The star birth occurs during compression of gas and dust clouds, at sufficiently high compression ratio when heating in the center of the star is sufficient to "ignition" fusion reactions. The death of the star occurs when the star ceases to be in a stable condition under normal parameters (density, size, somehow comparable to the sun). In this sense, the death of a star comes in different ways, depending on its initial mass.

The death of the star occurs when the star ceases to be in a stable condition under normal parameters (density, size, somehow comparable to the sun)

The death of a star with mass M<0,5 the sun passes through the following scenario. The star unable to convert helium even after in the core reactions stop involving hydrogen - its mass is too small to provide a new compression phase of gravity to the extent that initiates the "fire" the helium. These stars are red dwarfs, such as Proxima Centauri, which stay on the main sequence is from tens of billions to tens of trillions of years. After the cessation in their nucleus thermonuclear reactions, they gradually cooling down, will continue to radiate weakly in the infrared and microwave bands of the electromagnetic spectrum.

If 0,5

If M>3,3 the death of the star marks the formation of a black hole. For example, once a star with a mass greater than five solar, is in a red supergiant stage, its core by gravity begins to shrink. As the compression increases the temperature of the star and its density, and begins a new sequence of fusion reactions. In all such reactions are synthesized heavier elements: helium, carbon, oxygen, silicon and iron, which temporarily restrains the core collapse. Ultimately, as the formation of all heavier elements of the periodic system, it is synthesized from silicon-iron 56. At this stage, a further fusion becomes impossible because the iron-core 56 has a maximum mass defect and the formation of heavier nuclei with energy release is impossible. Therefore, when the iron core of the star reaches a certain size, the pressure in it is no longer able to resist the gravity of the outer layers of the star, and there is an immediate collapse of the nucleus, while the radius of the star will not be smaller than the Schwarzschild. After that, the star becomes a black hole.

All cases of death of a star can be observed, and all of them - the result of depletion of fuel. Neutron stars and black holes manifest themselves in a particular type of radiation spectrum and nature of the impact on ordinary stars of the satellite.

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