About J2229+6205
J2229+6205 is an uncommon pulsar. It spins once every 443.055 ms, has a dispersion measure of 124.64 pc cm⁻³ and carries a surface magnetic field around 1.01×10^12 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.