About J0243+6027
J0243+6027 is an uncommon pulsar. It spins once every 1,473 ms and has a dispersion measure of 141 pc cm⁻³.
The collapsed core of a star that exploded: about one and a half Suns of matter crushed into a ball the size of a city, held up only by the refusal of neutrons to be squeezed further.