About J2208+4610
J2208+4610 is a rare pulsar. It spins once every 642.506 ms, has a dispersion measure of 63.41 pc cm⁻³ and carries a surface magnetic field around 4.20×10^10 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.