The Hottest Superfluid and Superconductor in the Universe: Discovery and Nuclear Physics Implications

We present recent work on using astronomical observations of neutron stars to reveal unique insights into nuclear matter that cannot be obtained from la boratories on Earth. First, we discuss our measurement of the rapid cooling of the youngest neutron star in the Galaxy; this provides the first direct evidence for superfluidity and superconductivi ty in the supra-nuclear core of neutron stars. We show that observations of thermonuclear X-ray bursts on neutron stars can be used to constrain properties of neutron superfluidity and neutrino emission. We describe the implications of rapid neutron star rotation rates on aspects of nuclear an d superfluid physics. Finally, we show that entrainment coupling between the neutron superfluid an d the nuclear lattice leads to a less mobile crust superfluid; this result puts into question the c onventional picture of pulsar glitches as being solely due to the crust superfluid and suggests that t he core superfluid also participates.