About J1921-0510
J1921-0510 is an uncommon pulsar. It spins once every 794.254 ms, has a dispersion measure of 96.6 pc cm⁻³ and carries a surface magnetic field around 7.00×10^11 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.