About J1640-4631
J1640-4631 is an uncommon pulsar. It spins once every 206.443 ms and carries a surface magnetic field around 1.44×10^13 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.