About J1301+0833
J1301+0833 is an epic pulsar. It spins once every 1.844 ms, has a dispersion measure of 13.2 pc cm⁻³ and carries a surface magnetic field around 141,164,410 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.