Webb Spots Chemical Weather on Brown Dwarfs ⚡ экспресс
A new analysis of the spectroscopic variability of the brown dwarf binary system WISE J104915.57-531906.1AB (L7.5+T0.5) is presented, based on data from the NIRSpec instrument aboard the James Webb Space Telescope (program GO 2965). The variability of the main molecular bands (H₂O, CH₄, CO) in the 0.6–5.3 μm range was studied. Component B exhibits a higher maximum deviation than A across all investigated bands. The light curves reveal a dependence of variability on wavelength and possibly chemical composition. In particular, for component A, the variability in CH₄ and CO absorption lines is higher than that of H₂O, even at similar pressure levels. It is concluded that clouds alone cannot explain the enhanced variability of CO and CH₄ relative to H₂O; an additional physical mechanism—thermochemical instabilities—is likely required. A three-dimensional visualization of the atmospheric structure of both components was constructed, based on the contribution of molecular bands at different pressures and accounting for planetary waves.
Brown dwarfs are heavier than planets but lighter than stars. Their atmospheres resemble a bubbling pot: clouds of scorching sand and iron droplets rise and fall. The Webb Telescope long monitored the pair WISE 1049AB and, breaking their light into colors, noticed a puzzle: the warmer dwarf's light from methane and carbon monoxide pulses far more strongly than from water, even though all three originate from the same depth. Clouds aren't to blame—turbulent chemical reactions rage in the depths. Like a pot where some spices float faster than others when heated, these reactions speed up and stall, rippling the glow.
Additionally, gigantic waves course through the atmosphere—exactly like those that create weather on Earth, only without oceans or land. This chemical dance could be the key to forecasting climate on distant planets.
🎯 Similar chemical waves likely rage in Jupiter's atmosphere—we just can't see them directly.