ALMA

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. The strange phenomenon inspired a new classification of stars sharing the same name (FUor stars). FUor stars flare suddenly, erupting in brightness, before dimming again many years later. It is now understood that this brightening is due to the stars taking in energy from their surroundings via gravitational accretion, the main force that shapes stars and planets. However, how and why this happens remained a mystery—until now, thanks to astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA).

Astronomers have discovered the secrets of a starburst galaxy producing new stars at a rate much faster than our…