If you want to become a white dwarf after death, the star must be a small star. In the process of death, a star shell and a star core are formed. The shell is thrown outward and the core collapses inward. If the mass of the star core does not exceed 1.44 times that of the sun, a white dwarf will be formed. When the white dwarf is under high pressure, the atoms are crushed, and the electrons will be out of orbit and become free electrons.
Generally speaking, the mass of such a star before its death is about 0/0 times that of the small 8 of the sun. According to theoretical speculation, white dwarfs account for about 10% of the total number of stars.
If a star wants to become a neutron star, its mass must be more than 8~ 10 times and less than 30 times of the mass of the sun, so as to ensure that a supernova explosion occurs when the star dies, and the mass of the core after the explosion remains between 1.44~3.2 times of the mass of the sun. Finally, under high pressure, not only atoms but also nuclei are crushed, and protons and electrons combine to form neutrons. Finally, all neutrons.
A neutron star is not the final state of a star, but it can evolve further. When its energy is exhausted, the neutron star will become a black dwarf without light. White dwarfs can actually become black dwarf, but it will take a long time and 20 billion years.
Let's talk about the last state after the death of a star, which is also the most mysterious and unknown state: a black hole.
If you want to become a black hole after death, the mass of the star before death must be more than 30 times that of the sun, and the mass of the core after explosion must be more than 3.2 times that of the sun, so as to form a mysterious and unknown black hole.
Extended data
Human observation of stars has a long history. The ancient Egyptians predicted the Nile flood the moment Sirius appeared on the eastern horizon. The Shang Dynasty in China set up special officials to observe the appearance of the Great Eastern Mars (Antares) and determine the start time of the year. In the process of observation, the Song Dynasty discovered the supernova of Taurus-the celestial official guest star. Sailors in the Ming Dynasty used the navigation of nine planets to judge their direction.
Many ancient astronomers believed that stars were fixed on the eternal celestial sphere and would never change. Traditionally, astronomers combine the stars into constellations or stars and use them to determine the motion of planets in the sky. The cycle of the sun's movement under the starry sky background is used to create calendars and guide agricultural time.
The Gregorian calendar, which is used almost all over the world now, is based on the nearest star, the sun.
The oldest star map with accurate date appeared in ancient Egypt in BC 1534. The Arabic names given to many stars by Islamic astronomers are still in use today. They also invented many astronomical instruments to measure and calculate the position of stars. However, for a long time, people still misunderstood stars.
1584, giordano bruno developed Nicholas Copernicus's Heliocentrism, thinking that the stars in the sky, like the sun, may also have other planets, so he was regarded as a "heresy". Democritus and Epicurus, ancient Greek philosophers, also put forward the same view with him. /kloc-after Newton discovered gravity in the 0 th and 7 th centuries, people's misunderstanding of stars gradually disappeared.
1838, Bessel first measured the distance of a star (cygnus 6 11.4 light years), revealing the vastness of space and the distance between celestial bodies. William Herschel was the first astronomer who tried to determine the distribution of stars in the sky. 1780s, he made a series of measurements in 600 directions with measuring instruments, and calculated the number of stars that could be seen along the line of sight, thus drawing the first galaxy star map (silver disk).
Joseph Fraunhofer and Angelo Sich are pioneers of scientific celestial spectroscopy. They found that the dark lines in the star spectrum are caused by the absorption of specific frequencies and wavelengths by the atmosphere. In the 20th century, the study of stars began to turn to the physical direction. 19 13 years, Herotto came out, which promoted the study of stellar physics and successfully put forward the explanation of the internal structure of stars and the model of stellar evolution.
Because of the development of quantum mechanics, the problems in the star spectrum can also be solved well. In today's world, due to the rapid development of science and technology, various telescopes are constantly being built, and the study of stars by human beings is becoming more and more detailed.