About J1555-0515
J1555-0515 is an uncommon pulsar. It spins once every 975.41 ms, has a dispersion measure of 23.46 pc cm⁻³ and carries a surface magnetic field around 1.43×10^12 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.