About J2124-3358
J2124-3358 is a rare pulsar. It spins once every 4.931 ms, has a dispersion measure of 4.6 pc cm⁻³ and carries a surface magnetic field around 322,280,942 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.