Why are there positrons in stars? Why do stars become neutron stars?

Because in the hydrogen-hydrogen fusion of stars, two hydrogens first fuse to form helium-2, but helium-2 is an extremely unstable element, which will immediately decay and release a positron and become hydrogen 2, which is a stable element.

The reaction formula is: h + h - h2 + positron, accompanied by the release of an electron neutrino. This is the first step in the hydrogen fusion reaction process.

Because there is so much hydrogen fusion, positrons are also produced in large quantities, but due to frequent interactions with stellar matter, positron radiation is not very strong; But neutrinos rarely interact with ordinary matter, so there are a lot of neutrinos gushing out of the sun's interior.

LZ is talking about positron?? In a general sense, electrons are negatively charged, and positively charged electrons only exist in the most mysterious matter --- antimatter in the universe, and antimatter emits a lot of energy when it collides with positive matter. Rays and X-rays are an effective way for stars to emit energy, but antimatter will annihilate after colliding with positive matter, so the mass of the star will continue to decrease, and finally the gravity of the matter outside the nucleus will be less than the tension on the outside of the star's nucleus, causing the star to expand extremely much to form a red giant, and then the stellar nucleus continues to consume matter, and finally the tension on the outside of the stellar nucleus is less than the gravity of the star itself, compressing inward, emitting a lot of light and heat, and after running out of energy, it becomes a white dwarf, and the energy released by antimatter is very large 1kg of antimatter according to the famous formula:

E=mc 2 E is energy, m is mass, c is the speed of light, and you can release 9*10 16j energy, which is enough energy to power the whole earth for a year, but it is very difficult to make antimatter, and scientists are trying to make antimatter, but it took 10 years to extract only gram of antimatter, because antimatter releases a lot of energy, so there is still some antimatter in the star.

Positrons are created in stellar thermonuclear fusion.

However, positrons are antimatter that collide with matter in the inner core of a star and become Y-rays and energy.

It is estimated that this is also the second largest reason for the rapid emaciation of stars in addition to the star wind.

You're talking about antimatter, oh my God

When a star ages, its thermonuclear reaction has exhausted the fuel (hydrogen) of the center, and there is not much energy produced by the center. In this way, it no longer has enough strength to carry the enormous weight of the shell. So under the weight of the shell, the core begins to collapse until it finally forms a small, dense star that regains its ability to balance with the pressure.

Stars with less mass mainly evolve into white dwarfs, while stars with more mass may form neutron stars. And according to the calculations of scientists, the total mass of a neutron star cannot be greater than three times the mass of the Sun. If this value is exceeded, there will be no force left to compete with its gravity, causing another collapse.

It is no more than 3 times the mass of the sun.