About J2017+0603
J2017+0603 is an epic pulsar. It spins once every 2.896 ms, has a dispersion measure of 23.92 pc cm⁻³ and carries a surface magnetic field around 153,965,105 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.