About J1554-5512
J1554-5512 is an uncommon pulsar. It spins once every 3,418.039 ms, has a dispersion measure of 450 pc cm⁻³ and carries a surface magnetic field around 1.04×10^13 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.