Unfortunately, this relaxation time is of the same order as the PWD cooling time, and so only the cool end of the sequence would see the full effects of the new rates on their evolutionary timescales. 6.3 Pre-White Dwarf Sequences with Different Neutrino Rates Starting with the PWD seed models above, we evolved the models from high L and down toward the white dwarf cooling track. Three sequences were calculated. The base sequence used the normal neutrino production rates. This trio spans nearly one order of magnitude in neutrino production.
Luminosity decreases by almost four orders of magnitude in approximately five million years.
Evolutionary tracks for three model sequences with different input neutrino production rates. In Figure 6.2, we find that, for all three sequences, neutrino losses are the primary cooling mechanism over the approximate range . The ratio also increases with stellar mass. Figures 6.1 and 6.2 show that the differences in L and are smallest when the neutrinos are important. Even at high luminosity, however, different neutrino rates result in only small changes in measurable quantities such as surface gravity.