Neutron stars are the remnants of massive stars that have exploded in a supernova. After the explosion, the core of the star collapses into an incredibly dense object made almost entirely of neutrons. These stars are only about 1.5 times more massive than the Sun, but they can be as small as 20 kilometers in diameter, making them incredibly dense.
Neutron stars possess extreme magnetic fields and rotate rapidly, making them fascinating objects for study. Some neutron stars are even classified as pulsars because of their regular pulse of radiation. The study of neutron stars helps scientists understand the behavior of matter under extreme conditions and the nature of space-time.