About J0540-7125
J0540-7125 is an uncommon pulsar. It spins once every 1,286.015 ms, has a dispersion measure of 29.41 pc cm⁻³ and carries a surface magnetic field around 1.04×10^12 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.