A Submillimeter Burst of S255IR SMA1: The Rise and Fall of Its Luminosity

Temporal photometric variations at near-infrared to submillimeter wavelengths have been found in low-mass young stellar objects. These phenomena are generally interpreted as accretion events of star-disk systems with varying accretion rates. There is growing evidence suggesting that similar luminosity flaring also occurs in high-mass star/cluster-forming regions. We report in this Letter the rise and fall of the 900 m continuum emission and the newly found 349.1 GHz methanol maser emission in the massive star-forming region S255IR SMA1 observed with the Submillimeter Array and the Atacama Large Millimeter/submillimeter Array. The level of flux variation at a factor of ∼2 at the submillimeter band and the relatively short 2 years duration of this burst suggest that the event is probably similar to those milder and more frequent minor bursts seen in 3D numerical simulations.