About J1402-5021
J1402-5021 is an uncommon pulsar. It spins once every 1,380.182 ms, has a dispersion measure of 51 pc cm⁻³ and carries a surface magnetic field around 2.77×10^12 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.