Confronting Neutron Star Cooling Theories with New Observations

With the successful launch of Chandra and XMM/Newton X-ray space missions combined with the lower energy band observations, we are now in the position where careful comparison of neutron star cooling theories with observations will make it possible to distinguish among various competing theories. For instance, the latest theoretical and observational developments appear to exclude both nucleon and kaon direct Urca cooling. In this way we can now have realistic hopes for determining various important properties, such as the composition, degree of superfluidity, equation of state, and stellar radius. These developments should help us obtain better insight into the properties of dense matter.