About J1809-1850
J1809-1850 is an uncommon pulsar. It spins once every 1,124.481 ms, has a dispersion measure of 598 pc cm⁻³ and carries a surface magnetic field around 3.49×10^12 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.