About J1901+0234
J1901+0234 is an uncommon pulsar. It spins once every 885.24 ms, has a dispersion measure of 404 pc cm⁻³ and carries a surface magnetic field around 4.57×10^12 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.