JWST peers into the freezing atmosphere of the distant giant planet L 97-3 b (WD 0806 b)

Star system: L 97-3 | Distance from the Sun: 62.7 light years

Using the James Webb Space Telescope (JWST), astronomers have conducted a detailed analysis of WD0806 b, one of the coldest planets ever photographed outside our Solar System. Orbiting a white dwarf at a massive distance—about 60 times further than Pluto is from our Sun—this gas giant has temperatures of only 350 K (roughly 77°C). The study identified a cocktail of chemicals in its atmosphere, including water, methane, and carbon dioxide. 

For the first time, researchers were able to measure how gases mix at different altitudes, discovering that the atmospheric churning slows down as you move higher up. With a mass about eight times that of Jupiter, this planet provides a unique laboratory for understanding how cold, isolated worlds evolve far from the warmth of a typical star.

Scientific study

JWST spectral retrieval of cold directly imaged planet WD0806 b and the first measurement of altitude-dependent K_{zz} in exoplanet atmospheres (external link)