Bolometric (solid) and optical (dashed; integrated from 3500 Å to 8000 Å) LCs from the explosions of the extended (1962 R_⊙) hydrogen-free ULGRB progenitor. The ejecta mass is 15 M_⊙ and the explosion energy is shown in the figure. All the models have 0.1 M_⊙ of ⁵⁶Ni, but it does not affect the LCs presented here as indicated by the total nuclear energy available from 0.1 M_⊙ of ⁵⁶Ni (red; Nadyozhin 1994).