About J1813-2621
J1813-2621 is an epic pulsar. It spins once every 4.43 ms, has a dispersion measure of 122.49 pc cm⁻³ and carries a surface magnetic field around 237,802,257 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.