About J0038-2501
J0038-2501 is an uncommon pulsar. It spins once every 256.926 ms, has a dispersion measure of 5.71 pc cm⁻³ and carries a surface magnetic field around 1.41×10^10 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.