About J1818-1541
J1818-1541 is an uncommon pulsar. It spins once every 551.134 ms, has a dispersion measure of 690 pc cm⁻³ and carries a surface magnetic field around 2.34×10^12 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.