Astronomers Solve the 1936 Mystery of FU Orionis’ Dramatic Outburst

ALMA observations of FU Orionis reveal how gravitational accretion from a past gas stream causes sudden brightness in young stars, shedding light on star and planet formation processes.

An unusual group of stars in the Orion constellation have revealed their secrets. FU Orionis, a double star system, first caught astronomers’ attention in 1936 when the central star suddenly became 1,000 times brighter than usual. This behavior, expected from dying stars, had never been seen in a young star like FU Orionis.