About J1906+0509
J1906+0509 is an uncommon pulsar. It spins once every 397.59 ms, has a dispersion measure of 99.5 pc cm⁻³ and carries a surface magnetic field around 1.46×10^12 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.