About J0646+0905
J0646+0905 is an uncommon pulsar. It spins once every 903.913 ms, has a dispersion measure of 147.85 pc cm⁻³ and carries a surface magnetic field around 8.25×10^11 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.