About J1849+2559
J1849+2559 is an uncommon pulsar. It spins once every 519.263 ms, has a dispersion measure of 75 pc cm⁻³ and carries a surface magnetic field around 3.09×10^11 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.