Dependence of the bolometric light curve and the mass fractions at t = 50 days on the explosion energy for the late-time 1D simulations with the representative radioactive ⁵⁶Ni mass from Table 2. Panel a): light curves of models B15-1 (green solid line), B15-2 (blue solid line), and B15-3 (magenta solid line) compared with the observations of SN 1987A obtained by Catchpole et al. (1987, 1988) (open circles). The light curves of the corresponding models without radioactive ⁵⁶Ni are shown with dotted lines. Panels b)−d): mass fractions as functions of velocity in models B15-1, B15-2, and B15-3, respectively. The red line is the mass fraction of radioactive ⁵⁶Ni, and the magenta line represents iron-group elements except for ⁵⁶Ni (see also Fig. 2).