Evolution of a 3000 M_⊙ model at a constant accretion rate. Left panel: HR diagram depicting the evolution of a model until the end of core silicon burning with a constant accretion rate of 10⁻³ M_⊙ yr⁻¹. The black line represents the ZAMS line for Z = 0 metallicity. The star symbol on the track represents the start of core hydrogen burning when the mass of the model is 62.8 M_⊙. Right panel: evolution of the central temperature versus the central density of the model. The blue line marks a 120 M_⊙ model at Z = 0 metallicity, starting from ZAMS and ending at core helium burning.