How are black holes formed? Where is the nearest black hole to the earth?

The process of a black hole is similar to that of a neutron star. A star is preparing to die, and its core rapidly contracts, collapses and explodes under its own gravity. When all the core materials become neutrons, the contraction process stops immediately and is compressed into dense stars, and the inner space-time is also compressed. But in the case of a black hole, because the mass of the star core is so great that the contraction process goes on endlessly, the neutron itself is ground into powder under the attraction of the squeezing gravity itself, and the rest is the matter with unimaginable density. Due to the power generated by high quality, anything close to it will be sucked in by it. Black holes began to devour the shells of stars, but black holes could not devour so much matter. Black holes release some substances and emit two kinds of pure energy-gamma rays.

1 The brightest star in α-Sirius Canis one of the six stars in the Great Ellipse in winter. Its companion star is the first confirmed white dwarf star in the whole sky and the closest to the earth.

This neutron star is located in Ursa minor and is now named "Calve La" by astronomers. If further confirmed, Calfra will be the eighth isolated neutron star, which has no supernova remnants and no stars and radio waves around it.

The nearest black hole is about 1600 light-years away from the earth. This black hole is located in Sagittarius, and it forms a binary system with an ordinary star numbered V464 1SGR.