About J1727-2951
J1727-2951 is a rare pulsar. It spins once every 28.405 ms, has a dispersion measure of 215.1 pc cm⁻³ and carries a surface magnetic field around 3.00×10^9 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.