About J1840-1419
J1840-1419 is an uncommon pulsar. It spins once every 6,597.563 ms, has a dispersion measure of 19.4 pc cm⁻³ and carries a surface magnetic field around 6.55×10^12 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.