About J1813+1822
J1813+1822 is an uncommon pulsar. It spins once every 336.425 ms, has a dispersion measure of 60.8 pc cm⁻³ and carries a surface magnetic field around 8.51×10^10 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.