About J0007+7303
J0007+7303 is an uncommon pulsar. It spins once every 315.873 ms and carries a surface magnetic field around 1.08×10^13 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.