  We demonstrate that there exists a new mechanism for dissipating the energy
of stellar oscillations. For neutron stars, in particular, we show that the
mechanical energy of density perturbations is not only dissipated to heat via
bulk viscosity, but also that energy is radiated away via neutrinos. This
energy dissipation will be associated with a viscosity coefficient, the
radiative viscosity, which is larger than the bulk viscosity in the case of
non-strange quark matter and nuclear matter.
