Multiple snapshots of the α = 10⁻⁵, β = 1, 8 cps model showcasing the vortex merging process during the early stage of gap opening, the fully grown size of the resulting vortex, and its subsequent decay. The surface density and vortensity contrast compared to their initial profiles is shown in the left and right panels, respectively. Time is quoted in units of planetary orbits. The horizontal line at r = 1.45 r_p serves to highlight the outward radial movement of those structures as the gap around the planet grows wider. The planet is located at r = 1 r_p and ϕ = 0.