Enclosed mass as a function of radius in the protostar calculated from Eq. (10), assuming a total stellar mass of 10⁵ M_⊙ and mass accretion rates ṁ = 0.1,1.,10. The current time t is calculated as t = (M/M_⊙)/ṁ. For a given mass shell, higher accretion rates imply larger radii, as the star had less time to contract.