Integrated flow time of the wind (axis on the right) from the calculated velocity law shown in Fig. 10 of Schmutz (1997). The velocity law is shown in black and the cumulative flow time of the wind in red, starting at the photosphere, where the wind optical depth is τ = 1. This corresponds to the model radius 3 R_* (= 10 R_⊙). The blue rectangle encloses the distance between the two stars at periastron, 26 R_⊙ (= 0.87 log₁₀(r/R_*)), and apastron, 32 R_⊙ (= 0.96 log₁₀(r/R_*)).