About J1342+2822A
J1342+2822A is an epic pulsar. It spins once every 2.545 ms and has a dispersion measure of 26.5 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.