About J1031-6117
J1031-6117 is an uncommon pulsar. It spins once every 306.411 ms, has a dispersion measure of 506.8 pc cm⁻³ and carries a surface magnetic field around 7.48×10^11 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.