About J1849+0430
J1849+0430 is an uncommon pulsar. It spins once every 421.126 ms, has a dispersion measure of 191 pc cm⁻³ and carries a surface magnetic field around 2.21×10^11 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.