Astronomers Find Evidence of Extreme Weather on Brown Dwarf

Posted on September 12, 2011

A University of Toronto-led team of astronomers has observed extreme brightness changes on a nearby brown dwarf. The astronomers say the brightness may indicate a storm grander than any seen yet on a planet. The astronomer say that because old brown dwarfs and giant planets have similar atmospheres, the discovery could help shed new light on weather phenomena of extra-solar planets.

The scientists used an infrared camera on the 2.5m telescope at Las Campanas Observatory in Chile to capture repeated images of a brown dwarf named 2MASS J21392676+0220226, or 2MASS 2139 for short, over several hours. In the short time span, they recorded the largest variations in brightness ever seen on a cool brown dwarf.

"We found that our target's brightness changed by a whopping 30 per cent in just under eight hours," said PhD candidate Jacqueline Radigan, lead author of a paper to be presented this week at the Extreme Solar Systems II conference in Jackson Hole, Wyoming and submitted to the Astrophysical Journal. "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."

"We might be looking at a gigantic storm raging on this brown dwarf, perhaps a grander version of the Great Red Spot on Jupiter in our own solar system, or we may be seeing the hotter, deeper layers of its atmosphere through big holes in the cloud deck," said co-author Professor Ray Jayawardhana, Canada Research Chair in Observational Astrophysics at the University of Toronto.

You can read the research paper here. You can see a larger version of the Artists's Impression of the brown dwarf here.



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