About J1739-3023
J1739-3023 is an uncommon pulsar. It spins once every 114.372 ms, has a dispersion measure of 170.5 pc cm⁻³ and carries a surface magnetic field around 1.16×10^12 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.