Profiles for the original model as the WD evolves toward cooler Teff. The upper panel shows the neutrino cooling rate, which dominates the interior regions of the WD for the Teff = 29,765 K curve, yielding ﹩{L}_{r}\,{/}\!\!\!\!\!\!{\propto }\,{M}_{r}﹩. The luminosity profiles in the lower panel show that ﹩{L}_{r}\propto {M}_{r}﹩ does not occur until Teff ≲ 20,000 K.