via Ka Leo O Hawaii: UH Manoa Student College Newspaper & Media – UH astronomers help discover weather patterns of binary brown stars.

Through the Keck Telescopes on Mauna Kea, a team of astronomers from University of Hawai’i, Massachusetts Institute of Technology and California Institute of Technology discovered an unusual image of binary brown dwarf stars. The mass of a brown dwarf determines its brightness; the more massive a brown dwarf is, the brighter it shines. But images taken from the Keck Telescopes revealed an anomaly: The 2M1404B brown dwarf emitted 60 percent more radiation than the higher-mass 2M1404A brown dwarf. “The reason could be the change in weather patterns or change in the cloud structure,” said Dagny Looper, UH graduate student and lead author of the study. Although formed similarly to normal stars, brown dwarf stars are the size of Jupiter, increasing their mass. Brown dwarfs also have the ability to cool down when their temperatures become too hot so they have cloud decks. “Brightening is coming because cloud decks are collapsing,” Looper said. “The process by which the clouds suddenly disappear is still unknown,” said Adam Burgasser, an assistant professor at MIT. “But similar brightenings have been seen in clear patches in Jupiter’s cloud decks. There appears to be a connection between the clouds on planets and the clouds on a brown dwarf.” The Keck Telescopes are breaking down barriers for scientists to view these celestial phenomena. “Like many other brown dwarf binaries, the separation in the sky between the two components is very small,” wrote Chris Gelino, an astronomer at the Spitzer Science Center at Caltech in a recent article. Looper said that this was a very difficult experiment. “We have to find the binary stars through observation to show that they are binary stars,” he said. “Binary stars are 10 percent of the whole sky.” Three images of the stars will be taken simultaneously from the Keck Telescopes each semester. The team will continue researching brown dwarfs to observe whether the cloudy behavior is consistent.