About J1739-3951
J1739-3951 is an uncommon pulsar. It spins once every 341.772 ms, has a dispersion measure of 24.6 pc cm⁻³ and carries a surface magnetic field around 8.34×10^10 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.