About J2003+2916
J2003+2916 is an uncommon pulsar. It spins once every 1,009.877 ms, has a dispersion measure of 209.5 pc cm⁻³ and carries a surface magnetic field around 5.94×10^11 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.