Too young to be so cool: Lessons from three neutron stars

ESA's XMM-Newton and NASA's Chandra spacecraft have detected three young neutron stars that are unusually cold for their age. By comparing their properties to different neutron star models, scientists conclude that the oddballs' low temperatures disqualify around 75% of known models. This is a big step towards uncovering the one neutron star "equation of state" that rules them all, with important implications for the fundamental laws of the universe.