Usually a neutron star, or a black hole, depending on the remaining mass.
This is a supernova.
When a supergiant star exhausts its nuclear fuel and dies, it may explode in a supernova event. Depending on its mass, the remnants can either collapse into a neutron star or form a black hole. The outcome is determined by the star's initial mass and the processes occurring during the supernova explosion.
A supernova (plural: supernovae or supernovas) is a stellar explosion that creates an extremely luminous object.Check the link given for more information.
After the red supergiant stage, a massive star will typically undergo a supernova explosion. This occurs when the star's core collapses, leading to a rapid expulsion of its outer layers. The remnant core may become a neutron star or, if the mass is sufficient, collapse further into a black hole. The supernova explosion also disperses heavy elements into space, contributing to the formation of new stars and planets.
A supernova, resulting in either a neutron star or black hole. Also may heavy elements are blown out of the star during the explosion.
No one knows for sure, since there is not enough information to figure it out. After a supernova, the star will either turn into a black hole, a neutron star, or a pulsar. But, there is no scientific evidence that proves which one the star will turn into after a supernova.
A star may become a white dwarf, a neutron star, or a black hole. Which option applies depends on the mass of the star - more specifically, how much mass is left at the end - for example, after a supernova explosion if there is one.
The range of masses for a supernova typically falls between about 8 to 50 times the mass of the sun. When a star that massive runs out of nuclear fuel, it undergoes a catastrophic collapse resulting in a supernova explosion. Smaller stars may end their lives in a different type of explosion called a nova.
Once a star's nuclear fusion has ended, it will collapse inside its core and become what is known as a white dwarf. Its outer layers will shoot out into the universe as planet nebula. If they are very large, stars will explode into a Supernova and their core will collapse into a black hole.
A supernova itself doesn't have a specific weight as it is not a single object but rather a stellar explosion marking the end of a star's life cycle. The mass involved in a supernova can vary widely, often between 1.4 to several tens of solar masses (the mass of our Sun). During the explosion, a significant portion of the star's mass is ejected into space, while the remnant core may collapse into a neutron star or black hole.
The process of the stellar explosion is called a "nova", or if powerful enough, a "supernova". The outer layers of gas are blown away into space, and this shell of fleeing gas is sometimes called a "supernova remnant", or more generally, a "nebula". For example, the Crab Nebula is the gas cloud left over after a supernova explosion which was brilliantly visible here on Earth in the year 1054.
After the supernova of a red giant, remnants such as a neutron star or a black hole can form, depending on the mass of the original star. If the star was especially massive, it may also result in a supermassive black hole or a hypernova explosion.