About J0307+7443
J0307+7443 is an epic pulsar. It spins once every 3.156 ms, has a dispersion measure of 6.34 pc cm⁻³ and carries a surface magnetic field around 236,196,282 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.