About J1702-4217
J1702-4217 is an uncommon pulsar. It spins once every 227.565 ms, has a dispersion measure of 629 pc cm⁻³ and carries a surface magnetic field around 5.15×10^10 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.