About J1630+3550
J1630+3550 is an epic pulsar. It spins once every 3.229 ms, has a dispersion measure of 17.45 pc cm⁻³ and carries a surface magnetic field around 262,733,603 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.