A neutron star is a very dense and compact star that is formed when a massive star undergoes a supernova explosion. Neutron stars are composed almost entirely of neutrons, hence the name, and have incredibly strong gravitational pull due to their high density. They are about 1.4 times the mass of our Sun but only about 12 miles in diameter. Neutron stars also have extremely strong magnetic fields and can rotate rapidly, emitting beams of radiation along their magnetic poles, which we observe as pulsars.
