Neutron stars are the densest objects in the known universe. To understand their incredible properties, imagine taking the entire sun and squeezing it into a sphere just 12 miles across. The result is a mind-bendingly dense and energetic object that defies our everyday understanding of matter.
As astronomer Jocelyn Bell Burnell put it, "They are like giant atomic nuclei, with the mass of a star compressed down to the size of a city."
Neutron stars are formed when a massive star exhausts its fuel and undergoes a supernova explosion. The outer layers of the star are blasted away, leaving behind a small, incredibly dense core composed almost entirely of neutrons. In fact, a teaspoon of neutron star material would weigh about a billion tons on Earth.
"The gravitational pull of neutron stars is so strong that they literally warp the fabric of space-time," says astrophysicist Sean Carroll. "They create intense magnetic fields that accelerate particles to tremendous energies, producing powerful beams of radiation that can be observed across vast distances."
One of the most remarkable features of neutron stars is their extreme rotational stability. "Neutron stars can spin at incredibly high speeds, up to hundreds of times per second, and maintain that rotation for millions of years," notes physicist and writer Brian Koberlein. "It's as if you took a figure skater and had them spin continuously for years on end without stopping."
