PTF 12dam & iPTF 13dcc follow-up

Both show excess emission at early times and a slowly declining light curve at late times. The early bump in PTF 12dam is very similar in duration (~10days) and brightness relative to the main peak (2-3mag fainter) compared to that observed in other SLSNe I. In contrast, the long-duration (>30days) early excess emission in iPTF 13dcc, whose brightness competes with that of the main peak, appears to be of a different nature.

We construct bolometric light curves for both targets, and fit a variety of light-curve models to both the early bump and main peak in an attempt to understand the nature of these explosions. Even though the slope of the late-time decline in the light curves of both SLSNe is suggestively close to that expected from the radioactive decay of ^56^Ni and ^56^Co, the amount of nickel required to power the full light curves is too large considering the estimated ejecta mass.