About J0557-2948
J0557-2948 is an uncommon pulsar. It spins once every 43.643 ms, has a dispersion measure of 49.03 pc cm⁻³ and carries a surface magnetic field around 1.81×10^9 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.