Astronomers Recorded Monster Storm on Tiny Misfit Star

The star, called a brown dwarf, is more massive than a giant planet but much lighter than most stars. Over a period of several hours, the star exhibited the largest brightness variations ever seen on a cool brown dwarf. According to graduate student Jacqueline Radigan of the University of Toronto they found that the target’s brightness changed by a whopping 30 percent in just under eight hours. The best explanation is that brighter and darker patches of its atmosphere are coming into our view as the brown dwarf spins on its axis. Scientists think climate patterns on brown dwarfs are similar to those on giant planets, so studying this super squall could help illuminate weather on alien planets. 

Clouds on giant planets and brown dwarfs are thought to form when tiny dust grains, made of silicates and metals, condense. The researchers observed the star, called 2MASS J21392676+0220226, using the infrared camera on the 2.5-meter telescope at Las Campanas Observatory in Chile. They made repeated observations over several months, and found that the brightness variations differed as the weeks wore on.