For stars less massive than 8 times the mass of our Sun:
* White Dwarf: The core of the star collapses into a dense, hot, and very small object called a white dwarf. This is essentially the leftover "ashes" of the star. White dwarfs are supported against further collapse by electron degeneracy pressure. They slowly cool down over billions of years, eventually becoming black dwarfs.
For stars more massive than 8 times the mass of our Sun:
* Neutron Star: The core of the star collapses even further, squeezing protons and electrons together to form neutrons. This results in a neutron star, which is incredibly dense and only a few kilometers across. Neutron stars are supported by neutron degeneracy pressure. They can also exhibit extreme magnetic fields and rapid rotation.
* Black Hole: If the core of the star is massive enough (more than 20 times the mass of our Sun), the gravitational force will be so strong that even neutron degeneracy pressure cannot resist it. The core collapses into a singularity, a point of infinite density. This creates a black hole, a region of spacetime where gravity is so strong that nothing, not even light, can escape.
Other remnants:
* Supernova Remnant: The explosion itself blasts out a huge cloud of hot gas and dust called a supernova remnant. These remnants can expand for thousands of years and can trigger the formation of new stars.
* Pulsar: Some neutron stars emit beams of radiation from their magnetic poles. If these beams happen to sweep past Earth, we observe them as pulsars, objects that appear to pulse at regular intervals.
In summary: The remnants of a supernova explosion can include a white dwarf, a neutron star, a black hole, a supernova remnant, and even a pulsar. What remains depends on the initial mass of the star.
