Equation Icon  4 4 τ = -5--a--- = -5-----a------- GW 64 μM 2 64 q(1 + q)M 31 ( )4 ( ) −3 = 2.2 × 108q−1(1 + q)−1 -a-- -M1---- yr, (1 ) R ⊙ 1.4M ⊙