About J2317+1439
J2317+1439 is an epic pulsar. It spins once every 3.445 ms, has a dispersion measure of 21.9 pc cm⁻³ and carries a surface magnetic field around 92,600,740 G.
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.