About J2111+2106
J2111+2106 is an uncommon pulsar. It spins once every 3,953.853 ms, has a dispersion measure of 59.3 pc cm⁻³ and carries a surface magnetic field around 3.62×10^12 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.