Five articles, three of which were accepted for publication in the journal “Nature” and two still under peer review, report various aspects of a study on the exoplanet WASP-39b. Many researchers participated in various ways in examining observations conducted with the James Webb Space Telescope focused in particular on the atmosphere of this very hot planet. Webb’s various instruments made it possible to detect a number of substances in WASP-39b’s atmosphere such as carbon monoxide, sodium, and potassium. For the first time, sulfur dioxide was detected in the atmosphere of an exoplanet and indicate that photochemical reactions are taking place.