About J1550-5317
J1550-5317 is an uncommon pulsar. It spins once every 1,421.124 ms, has a dispersion measure of 600 pc cm⁻³ and carries a surface magnetic field around 1.17×10^12 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.