About J2242+6950
J2242+6950 is an uncommon pulsar. It spins once every 1,664.501 ms, has a dispersion measure of 40.86 pc cm⁻³ and carries a surface magnetic field around 2.87×10^12 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.