About J0324+5239
J0324+5239 is an uncommon pulsar. It spins once every 336.62 ms, has a dispersion measure of 115.46 pc cm⁻³ and carries a surface magnetic field around 3.62×10^11 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.