Strangeness condensation and cooling of neutron stars

Possible effects of strangeness condensation, which has been estimated to occur in dense neutron matter at densities of 2.3--3.0 times nuclear matter density, are calculated with special reference to the cooling of the neutron star probably formed in SN1987A. Although the center of the neutron star will cool much faster in the presence of strangeness condensation than through conventional mechanisms, down to T\ensuremath{\sim}2\ifmmode\times\else\texttimes\fi{}${10}^{8}$ K at the present time, the heat conductivity of the neutron star is such that it will take at least a few tens of years for effects of this drop in temperature to reach the surface of the neutron star and be observable.