Black dwarf

Black dwarf

A dark dwarf is a theoretical stellar relic, especially a white dwarf which has become sufficiently cool that it does not emit significant heat or light anymore. Because the time needed for a white dwarf to reach this stage is calculated more than the present age of the universe (13.8 billion years), now there is no hope of any dark dwarf in the universe, and the best white dwarves The temperature of the universe is an observation boundary over the age of.

The name "Black Dwarf" has also been applied to those substrellar objects which do not have enough mass, which is less than 0.08 M hydrogen to maintain hydrogen-burning nuclear fusion. These items are now commonly referred to as Brown Dwarf, which was coined in the 1970s. Black Dwarf should not be confused with Black Hole, Black Star or Neutron Stars.

Formation of the black dwarf

A white dwarf is the main sequence of the star of the low or medium mass, the remains of the star (below 9 to 10 solar masses (below M it)) after it expulsion or expel all those elements for which sufficient temperature to fuse it happens. Which is left, is a dense area of electron-depleting substance, which is gradually cooled by thermal radiation, eventually becomes a dark dwarf. If the black dwarfs were present then it would be extremely difficult to detect, because, by definition, they would emit very little radiation. However, they will be able to detect through their gravitational effects. Different white dwarfs were cooled by astronomers under the 3900 K (M0 spectral class) using the 2.4-meter telescope of the MDM Observatory in 2012. Their age is estimated to be 11 to 12 billion years.

Because the development of the distant future of the stars depends on the physical questions, which are poorly understood, such as the nature of black matter and the probability and rate of proton decay, it is not properly known that white dwarves should be blackened How long will it take in. ,, IIIE, IVA Barrow and Tipler estimate that a white dwarf will take 1015 years to cool 5 K; However, if weak particles (WIMPs) are interconnected, then it is possible that interactions with these particles keep some white dwarf warmer for more than 1025 years. If the protons are not stable, white dwarfs will also be kept warm by the energy emitted from proton decay. For a fictional proton life of 1037 years, Adams and Laughlin calculated that proton decay would increase the temperature of the effective surface of an older solar-mass white dwarf to approximately 0.06 K. Although cold, it is considered warmer than the cosmic background, in the future radiation temperature is 1037 years.

Future of the Sun

Once the sun stops the helium in its original form and in about 8 billion years a planet nebula rejects its layers, it will become a white dwarf and, after the trillions of years, now anybody Will not emit light too. After that, the sun will not appear equal to the naked human eye, it will be removed optically even if the gravitational effect is clear. The estimated time of cooling enough to become a dark dwarf of the Sun is approximately 1015 (1 quadranty) year, although it can take a lot of time, if there is poor contact with the above mentioned weak particles (WIMPs).