For massive stars, which are larger than 8M☉, after the pressure drops low enough, gravity will suddenly take over and it will collapse in just seconds. The collapse produces something we call a supernova, which is a cataclysmic explosion of a star, marking the end of its life. Supernovae release massive amounts of energy which briefly outshine entire galaxies.
After a supernova explosion, very dense remnants of massive stars called neutron stars are left behind, primarily made up of neutrons. These stars are formed when electrons and protons in the star’s core are crushed together under intense gravity. They have powerful magnetic fields, extreme density, and rotate rapidly. These usually have a mass range of 1.4-2.0M☉.
Pressure is exerted when neutrons are packed together very tightly. This is called neutron degeneracy which acts as a stabilizing force that prevents the gravitational collapse of neutron stars.
Another result of a supernova is the creation of a region in spacetime with such a strong gravitational pull that nothing, not even light, can escape. These regions are called black holes. Stars that have a mass in the range of 2-3M☉ are likely to become black holes at the end of their life. These can have a mass about 3-50 times the mass of our sun.
