About J1854+0306
J1854+0306 is an uncommon pulsar. It spins once every 4,557.82 ms, has a dispersion measure of 192.4 pc cm⁻³ and carries a surface magnetic field around 2.60×10^13 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.