About J1637-4553
J1637-4553 is an uncommon pulsar. It spins once every 118.773 ms, has a dispersion measure of 193.23 pc cm⁻³ and carries a surface magnetic field around 6.23×10^11 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.