Time needed to reach NSE as a function of the temperature for different values of Y_e at a constant density of ρ = 3 × 10¹¹   g/cm³. Symbols corresponding to the same value of Y_e are connected by a solid line. Y_e = 0.50 is shown by squares, 0.45 by circles, 0.40 by triangles and 0.33 by diamonds.