Standard and nonstandard plasma neutrino emission revisited

On the basis of Braaten and Segel's representation of the electromagnetic dispersion relations in a QED plasma we check the numerical accuracy of several published analytic approximations to the plasma neutrino emission rates. As we find none of them satisfactory we derive a new analytic approximation which is accurate to within 4%\ where the plasma process dominates. The correct emission rates in the parameter regime relevant for the red giant branch in globular clusters are larger by about $10-20$% than those of previous stellar evolution calculations. Therefore, the core mass of red giants at the He flash is larger by about 0.005_ or 1% than previously thought. Our bounds on neutrino magnetic dipole moments remain virtually unchanged.