James Webb Telescope detects changing weather on brown dwarf WISE 0855

Astronomers using the James Webb Space Telescope have successfully observed changing weather patterns on WISE 0855, a brown dwarf located approximately 7.5 light-years from Earth. The object, which is similar in size to Jupiter but possesses twice its mass, is one of the coldest known brown dwarfs with an atmospheric temperature of about −8 °C.

By conducting 11 hours of continuous spectroscopic observations and recording light spectra every 15 minutes, a research team from the University of Arizona’s Steward Observatory was able to distinguish between cloud effects, chemical composition, and temperature. The study revealed the presence of water clouds that thicken and dissipate as the object rotates.

Researchers also detected rhythmic changes in carbon monoxide and phosphine, driven by internal heat rising from the object's interior in a process similar to a lava lamp. This marks the first time meteorology on a celestial body outside our solar system has been measured with enough resolution to observe real-time atmospheric changes.