Profiles for the original model as the WD evolves toward cooler T_eff. The upper panel shows the neutrino cooling rate, which dominates the interior regions of the WD for the T_eff = 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 T_eff ≲ 20,000 K.