James Webb Space Telescope detects variable water clouds on brown dwarf

Scientists from the University of Arizona, using observations from the James Webb Space Telescope, have discovered variable water clouds surrounding the brown dwarf WISE 0855. Unlike most clouds found outside the Solar System, which typically consist of silicates, iron, or salts, these water clouds change in thickness over time.

As the object rotates, the clouds become thicker and thinner, revealing different zones of cloudiness and temperature similar to Earth's weather patterns. Additionally, researchers detected rhythmic signals of carbon monoxide and phosphine, gases believed to be transported from the deeper, hotter layers of the brown dwarf to the upper atmosphere through convection.

This discovery was made possible through spectroscopy, which allows for the separation of light into different wavelengths. This method provides more specific data regarding atmospheric composition and temperature than traditional photometry, which can only detect general changes in brightness.