About J1012-4235
J1012-4235 is an epic pulsar. It spins once every 3.101 ms and has a dispersion measure of 71.65 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.