Effects of the porosity, accretion law and accretion duration on the evolution of the central temperature. Left panel: planetesimal with the terminal radius D = 1 km that accretes instantaneously at t₀ = 0 Ma and φ equal to either zero (solid line), or 0.4 (dashed line). In the subplot of the left panel: instantaneously accreting planetesimal with D = 100 km and t₀ = 2.51 Ma. Middle panel: linear accretion from R₀ = 1.2 km to D = 10 km at t₀ = 1.44 Ma with varying accretion duration t_accr. Right panel: non-instantaneous accretion within 1 Ma with t₀ = 1.44 Ma, R₀ = 1.2 km and D = 10 km in comparison to an instantaneously accreting planetesimal assuming the same parameters (solid line).