Left upper panel: Pre-SN evolution of stars of 60 M_⊙ and 80 M_⊙ (from the main sequence phase up to the core He depletion stage, see Limongi & Chieffi 2018), with solar (initial) metallicities and initial rotation velocities V_rot = 0 km s⁻¹ (solid lines) and V_rot = 300 km s⁻¹ (dotted lines). The yellow asterisk marks the position of G26 in the HR diagram. Right upper panel: initial radial profiles of density in the models defined in Table 1. Models with initial rotation velocities V_rot = 0 km s⁻¹ and V_rot= 300 km s⁻¹ are represented with solid and dotted lines respectively. Lower panels: initial radial profiles of mass fractions for the species considered for two representative models, one with a low explosion energy (left panel) and the other with a high explosion energy (right panel). In both cases, the model describes a ZAMS star of 60 M_⊙. The range of enclosed mass (x-axis) is very different in these models because of the different location of the mass cut (see Limongi & Chieffi 2018).