A mystery lurks inside the corpses of dead stars. Neutron stars, formed when certain types of stars die in supernova explosions, are the densest form of matter in the universe; black holes are the ...

Gravitational wave astronomy is starting to do more than confirm Einstein’s equations. It is turning into a precision tool for mapping the invisible, with theorists now arguing that ripples in ...

The matter inside a neutron star consists mostly of neutrons, with a few protons, electrons, and other sub-atomic particles. This matter is so dense that an entire neutron star, with a mass greater ...