A brown dwarf located 47 light-years away is behaving very strangely. The would-be star's brightness is constantly changing, fluctuating by as much as 30% in just eight hours. This could be an atmospheric disturbance that dwarfs Jupiter's Great Red Spot.
Brown dwarfs are objects that fall between the minimum mass of a dwarf star and the maximum mass of a gas giant — too big to be just a planet, but not big enough to ignite stellar fusion. That in-between status already puts them in a pretty sad position, and it only gets worse from there. One nearby brown dwarf is full of so many noxious gases that its atmosphere likely smells like "rotten eggs with a hint of ammonia", while another is actually colder than boiling water.
Now, the brown dwarf 2MASS J21392676+0220226 — 2MASS 2139 to its friends — has shown up to restore a bit of respect to its kind, in the form of an absolutely raging storm on its surface. Observations by astronomers at Chile's Las Campanas Observatory found the brown dwarf in a constant state of flux, its brightness dipping up and down at an unprecedented rate and magnitude. The most likely answer is that part of the brown dwarf are in fact darker than others, and we're seeing that change as the brown dwarf rotates.
Researcher Jacqueline Radigan of the University of Toronto adds:
"We found that our target's brightness changed by a whopping 30 per cent 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."
If that is indeed the case, then we're looking at one of the biggest super-storms ever found. Because of the brown dwarf's greater size, its storm would be far bigger than the Great Red Spot that has raged on Jupiter for nearly 200 years — and that storm is three times the size of Earth. Both of these atmospheric disturbances are the result of tiny grains of silicates and metals condensing into giant dust storms.
Read the original paper here. Artist's conception by Jon Lomborg.