Growing black holes: Observational evidence for stellar tidal disruption events

Three major feeding mechanisms have been studied in the context of black hole growth: accretion, black hole - black hole mergers, and tidal capture/disruption of stars. While there is ample evidence that accretion is ongoing in active galaxies, observational evidence for the two other processes remained elusive for many years. Given the intense theoretical work on these latter two processes, it is of great interest to see whether such events do occur in nature, how frequent they are, and which properties they show. In this contribution, I will give a review of observational evidence for stellar tidal disruption events concentrating on X-ray flares of giant amplitude detected from the centers of several galaxies. These represent the most dramatic variability events, in terms of amplitude, ever recorded among galaxies.