The weather report for the two brown dwarfs closest to Earth is severe: extremely hot with toxic chemicals and clouds of silicate particles. Using the James Webb Space Telescope, researchers examined these brown dwarfs, located six light-years away. The data revealed detailed atmospheric conditions, including multiple cloud layers at different depths.
Both brown dwarfs have atmospheres primarily composed of hydrogen and helium, with some water vapor, methane, and carbon monoxide, and temperatures around 925 degrees Celsius at cloud tops. The study, led by astronomer Beth Biller from the University of Edinburgh, produced the most detailed weather maps of brown dwarfs to date.
Brown dwarfs are larger than planets but smaller than stars and emit their own light due to their heat, though they lack nuclear fusion. Their clouds, unlike Earth’s water clouds, consist of hot silicate particles. The examined brown dwarfs, about 500 million years old, are similar in size to Jupiter but much more massive.
The rapid rotation of these brown dwarfs influences their weather patterns, potentially creating visible bands and vortices like Jupiter’s Great Red Spot. This research could inform future studies of weather on exoplanets.
Brown dwarfs are relatively common, with about 1,000 known compared to over 5,000 exoplanets. The Webb Telescope, operating mainly in infrared, offers unprecedented insights into the complex atmospheres of these celestial bodies.
Source – CGTN