About J2115+5448
J2115+5448 is an epic pulsar. It spins once every 2.603 ms, has a dispersion measure of 77.41 pc cm⁻³ and carries a surface magnetic field around 446,804,654 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.