Time needed for gap opening as a function of the planetary mass for α = 10⁻⁴ and h = 0.05. The gap opening time is defined as the time needed to reach the Σ∕Σ_unp = 0.1 threshold by gas accretion, therefore, we removed the time needed to reach the initial gap, t_gap,init (see Table 2). Top: gap opening time as a function of the planetary mass. Fixed-mass planets are represented by crosses and linearly fitted by the dashed gray line. For comparison, the time evolution of the planetary masses for the accretion rate enhanced by 10, fiducial accretion rate, and that reduced by 10 are represented by the dashed-dotted dark, solid gray, and dashed light lines, respectively. Their gap-opening masses are represented with the same symbol as in Fig. 12. For these disc parameters, the gap-opening mass and time of the accreting planet follow the predictions of the fixed-mass planets. The disc response time is therefore the dominant phenomenon for gap opening. Bottom: perturbed surface densities of the fixed-mass planets at gap opening time. Gap-opening mass and time are defined by the moment at which the surface density is Σ = 0.1Σ_unp.