The Kepler satellite was designed to search for Earth-sized planets in the habitable zone of stars by measuring dips in a star's brightness as orbiting planets sprint across the stellar disc (transits). Its sensitive camera stares at more than 150000 stars towards the constellations of Cygnus and Lyrae,and so far has found over 5000 exoplanet candidates. But Kepler also monitors the light fluctuations in all the other stars, even dips not caused by transits, or has found some weird situations.
Source: phys.org