About J1749-4931
J1749-4931 is an uncommon pulsar. It spins once every 445.822 ms, has a dispersion measure of 55.29 pc cm⁻³ and carries a surface magnetic field around 5.19×10^11 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.