The magnitude of the expected superfluid transition temperature and the form of the gap are obtained for regimes of neutron density expected in neutron-star cores. For neutron densities exceeding 1.5×${10}^{14}$ g ${\mathrm{cm}}^{-3\mathrm{}}$ the gap is anisotropic but nodeless, leading to thermodynamic properties of a conventional BCS-type superfluid.

• Received 16 February 1970

DOI:https://doi.org/10.1103/PhysRevLett.24.775