About J2002+3217
J2002+3217 is an uncommon pulsar. It spins once every 696.761 ms, has a dispersion measure of 142.21 pc cm⁻³ and carries a surface magnetic field around 8.66×10^12 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.