Astrophysicists from the University of Bath have developed a new method for pinpointing the whereabouts of extremely rare extragalactic objects. They hope their technique for finding 'changing-look quasars' will take scientists one step closer to unraveling one of greatest mysteries of the universe—how supermassive black holes grow. Quasars are believed to be responsible for regulating the growth of supermassive black holes and their host galaxies.