About J1730-2304
J1730-2304 is a rare pulsar. It spins once every 8.123 ms, has a dispersion measure of 9.63 pc cm⁻³ and carries a surface magnetic field around 409,738,449 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.