About J1537-5312
J1537-5312 is an epic pulsar. It spins once every 6.927 ms, has a dispersion measure of 117.69 pc cm⁻³ and carries a surface magnetic field around 335,410,889 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.