The closest brown dwarves to Earth are in the constellation Vela, about 6.5 light-years away, looking like a faint dot in the night sky. Actually, the dot is two brown dwarfs, the binary system called Luhman 16AB. These brown dwarves are about the same size as Jupiter, but 30 times their mass. But do they look like Jupiter?
Jupiter’s belts and zones are due to strong winds that run parallel to its equator. However, closer to the poles, the cloud patterns are created by storms. So, are brown dwarves dominated by global winds or localized storms?
Some earlier data and models suggested that there were no belts or zones, just local storms. But to answer this question, astronomers turned to NASA’s TESS exoplanet hunter telescope.
No telescope has enough resolution to take a detailed image of a brown dwarf. These telescopes observed over 100 rotations in Luhman 16AB and identified patterns that revealed the structure of the clouds.
Based on observations, scientists created a model for how Luhman 16B looks.
Using high-precision brightness measurements from NASA’s TESS space telescope, astronomers found that the nearby brown dwarf Luhman 16B’s atmosphere is dominated by high-speed, global winds akin to Earth’s jet stream system. This global circulation determines how clouds are distributed in the brown dwarf’s atmosphere, giving it a striped appearance. Image credit: Daniel Apai
The light zones have thin cloud decks illuminated by light from the interior. The dark zones have thick cloud decks that block light from the interior. In short, the appearance of Luhman 16B is dominated by powerful global wind patterns and not localized storms.
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