About J1805-1504
J1805-1504 is an uncommon pulsar. It spins once every 1,181.269 ms, has a dispersion measure of 225 pc cm⁻³ and carries a surface magnetic field around 5.75×10^11 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.