When a star is tidally disrupted by a supermassive black hole, a relatively large amount of gas is suddenly injected close to the black hole event horizon. The resulting flare of thermal emission can be detected in optical and X-ray surveys. Over the last decade, a few dozen stellar tidal disruption flares (TDFs) have been discovered, but our understanding of these events is rather poor. Fundamental properties, such as the origin of the optical emission or the fraction of events that yield relativistic jets, are currently unknown. In this talk, I will present two recent (and unexpected) discoveries that provide a completely new way to study TDFs: reprocessed infrared emission and short-lived radio flares.