Supernova To Superfluid - Science News

Supernova To Superfluid - Science News: Subsequent measurements revealed that its 2-million-degree surface had cooled by 4 percent over the decade since its discovery. “This was the first time anyone found a young neutron star clearly changing temperature,” says Craig Heinke, an astrophysicist at the University of Alberta in Edmonton, Canada, who reported the observations last year in Astrophysical Journal Letters.

Theorists had long speculated that a young neutron star should cool for the first 100 years after its creation. Neutrons can break down into protons, ejecting nearly massless particles called neutrinos that carry energy away from the star. But this energy-sapping Urca process (named for a money-sapping casino in Brazil) couldn’t account for the steep temperature drop seen by Chandra hundreds of years after the Cassiopeia supernova.