Modeling the UV/Optical Light Curve of Re-brightening Tidal Disruption Events

Abstract In recent years, a new subclass of tidal disruption events (TDEs) has been reported in the literature. The light curve of these TDEs shows a re-brightening feature in the decline phase after the first peak, which then leads to a second flare. The re-brightening TDEs challenge the existing light-curve fitting tools designed to handle a single flare. In this work, we present a model aimed at reproducing the light curve of the re-brightening TDEs, based on the scenario that the consecutive flares are produced by the same star that experienced two partial TDEs. We also developed a fitting code from this model and applied it to two re-brightening TDEs: AT 2022dbl and AT 2023adr. The light curves of both TDEs are well-fitted. Finally, we forecast the time and peak brightness of the next flare for these two TDEs so that observers can prepare to examine our model.