SN 1987A: evolution of the bolometric light curve contribution of the central neutron star.

The authors present a study of the bolometric light curve of SN 1987A. The bolometric luminosity evolution through day 800 has followed extremely well the early theoretical predictions by setting the energy input from radioactive decay of ≡0.07 M_sun⁵⁶Co. But after day 900, the bolometric luminosity decline began to slow down and the bolometric light curve was flatter than theoretical predictions; between day 900 and day 1200, the bolometric light curve exhibited a significant flattening. This bump has been known for some time, but the problem of its origin has scarcely been addressed theoretically. It is likely that the central neutron star could be an energy source, and the most likely radiation mechanism is accretion. By accreting the matter whose expanding velocity is lower than the escaping velocity, the central neutron star can supply enough additional energy to produce the observed bump and flattening of the bolometric light curve after day 900.