Magnetar Polarizes X-rays Up to 47%
Neutron stars are ultra-dense remnants of supernovae the size of a city. In the 1930s, Fritz Zwicky hypothesized their existence, and later Jocelyn Bell Burnell discovered pulsars — rapidly rotating neutron stars.
Radio Pulse of a Celestial Spinning Top
In the neighboring galaxy, the Large Magellanic Cloud, lives the binary system A0538-66. There, a neutron star — a tiny sphere the size of a city but heavier than the Sun — spins on its axis every 69 milliseconds.