About J0137+6349
J0137+6349 is an uncommon pulsar. It spins once every 717.963 ms, has a dispersion measure of 285.5 pc cm⁻³ and carries a surface magnetic field around 8.40×10^11 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.