The effect of ρ and T at the outer boundary, on the envelope solution. The solid blue line indicates our standard 23   M_⊙ He-model in the P_rad–P_gas plane. The dashed lines indicate solutions for which the boundary values for the density ρ, and the temperature T have been changed. The inflated zone between 2 and 6 R_⊙ (as indicated by the radius marks) is mainly affected by the choice of the temperature T at the outer boundary. Temperatures T ≳ 80 kK, can lead to a cut-off of the inflated zone.