About J1907+0731
J1907+0731 is an uncommon pulsar. It spins once every 363.676 ms, has a dispersion measure of 239.8 pc cm⁻³ and carries a surface magnetic field around 2.62×10^12 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.