"Swirling storm clouds" similar to Jupiter's "Great Red Spot" could be common on low-temperature brown dwarfs.
"As the brown dwarfs spin on their axis, the alternation of what we think are cloud-free and cloudy regions produces a periodic brightness variation that we can observe," Stanimir Metchev of the University of Western Ontario, Canada, said, a Stony Brook University news release reported. "These are signs of patchiness in the cloud cover."
Brown dwarfs form as stars in their early years, but never gain the mass to "fuse atoms continually and blossom into full-fledged stars," the news release reported.
The researchers believe brown-dwarf storms contain torrential winds, and could even display lightning more brilliant and dangerous than Jupiter's. These objects are too hot to contain rainstorms; instead the extreme weather could include clouds of hot salt, sand, or molten iron.
Researchers with the Spitzer program "Weather on Other Worlds" observed 44 brown dwarfs orbiting on their axis for about 20 hours using an infrared space telescope.
Past research has suggested some brown dwarfs contain treacherous weather, but the team was not expecting to see the phenomenon on such a high number of the space objects. The team observed turbulent weather on about half of the studied brown dwarfs.
Some of the brown-dwarfs could have been positioned so that their storms were hidden; meaning most or even all of the objects could contain intense weather.
"We needed Spitzer to do this," Metchev said. "Spitzer is in space, above the thermal glow of the Earth's atmosphere, and it has the sensitivity required to see variations in the brown dwarfs' brightness."
The team also found out that brown dwarfs spin much more slowly than they had expected.
"We don't yet know why these particular brown dwarfs spin so slowly, but several interesting possibilities exist," Heinze said. "A brown dwarf that rotates slowly may have formed in an unusual way -- or it may even have been slowed down by the gravity of a yet-undiscovered planet in a close orbit around it."
