Synchronization time computed with Eq. (33) using the results given in Fig. 3. The meaning of symbols stays the same as in Fig. 3. The continuous lines are the theoretical result obtained by using Eq. (2.5) from Zahn (2008), under the assumption of a uniform density structure (), and with  ⟨ ν ⟩  = 3.4 × 10¹² cm² s^-1. The top line is for β₀ = 1.2 and the bottom one for β = 2.0.