What type of celestial body is formed from the collapse of a massive star after a supernova explosion?

The collapse of a massive star after a supernova explosion can result in the formation of a neutron star, which is an incredibly dense remnant primarily composed of neutrons. When a star that has a mass greater than about 8 times that of our Sun exhausts its nuclear fuel, it undergoes a supernova explosion. The outer layers are expelled, while the core collapses under gravity.

During this core collapse, if the remaining mass is between about 1.4 to 3 times the mass of the Sun, the core stabilizes into a neutron star. Neutron stars possess extraordinary properties, including extremely high densities—one teaspoon of neutron-star material would weigh around 6 billion tons—and strong magnetic fields. This structure results from the combination of gravity forcing protons and electrons to combine into neutrons.

In contrast, if the remnant core exceeds about 3 solar masses, it continues to collapse and can form a black hole, which is another type of stellar remnant. A white dwarf, on the other hand, is formed from smaller stars (those less massive than our Sun) and represents a different endpoint in stellar evolution. A red giant phase occurs much earlier in a star's life cycle when it has not yet undergone supernova