About J1537+1155
J1537+1155 is a rare pulsar. It spins once every 37.904 ms, has a dispersion measure of 11.62 pc cm⁻³ and carries a surface magnetic field around 9.70×10^9 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.