About J1231-1411
J1231-1411 is an epic pulsar. It spins once every 3.684 ms, has a dispersion measure of 8.09 pc cm⁻³ and carries a surface magnetic field around 292,139,379 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.