About J1658-5324
J1658-5324 is a rare pulsar. It spins once every 2.439 ms, has a dispersion measure of 30.83 pc cm⁻³ and carries a surface magnetic field around 166,917,171 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.