Comparison of the early- and late-time 1D simulations for model B15-2 with the representative radioactive ⁵⁶Ni mass (Table 2). Panel a): bolometric light curves of the early-time (black line) and late-time (red line) 1D simulations compared with the observations of SN 1987A obtained by Catchpole et al. (1987, 1988) (open circles). Panels b) and d): mass fractions of hydrogen and radioactive ⁵⁶Ni, respectively, as functions of velocity for the early-time (black line) and late-time (red line) 1D simulations. Panel c): mass fractions as functions of velocity for the early-time 1D simulation. The red line is the mass fraction of radioactive ⁵⁶Ni (see also Fig. 2). All profiles of the mass fractions are given at t = 50 days.