Mestel cooling gives for white dwarfs of the same core composition and envelope opacity
PHYSICS · Subjective · Fermi University Physics · Astrophysics & Cosmology · Stellar structure, energy generation and evolution · Stellar death and compact objects
Stars from the Inside, Ch White dwarfs: the relativistic polytrope, the Chandrasekhar mass and a cooling clock
Problem
Mestel cooling gives tcool∝M5/7L−5/7 for white dwarfs of the same core composition and envelope opacity. Mestel's law puts a 0.6M⊙ carbon-oxygen white dwarf at L=1.0×10−4L⊙ after a cooling time of 4.4Gyr. Use this to estimate the cooling age of a 1.0M⊙ carbon-oxygen white dwarf observed at L=1.0×10−3L⊙.