Thanks to the space telescope, a team of astronomers detected with unprecedented precision two helium tails escaping from the exoplanet WASP-121b.
Thanks to the space telescope, a team of astronomers detected with unprecedented precision two helium tails escaping from the exoplanet WASP-121b.
Astronomers from the University of Geneva (UNIGE), the National Centre of Competence in Research PlanetS, and the Trottier Institute for Research on Exoplanets (IREx) at the University of Montreal (UdeM) have made a striking discovery using the James Webb Space Telescope (JWST). For the very first time, scientists have continuously monitored the atmosphere escaping from an exoplanet throughout a complete orbit. The result: the gas giant WASP-121b is surrounded not by one, but by two immense helium tails extending over more than half of its orbit around its star. These observations, combined with numerical models developed at UNIGE, provide the most detailed portrait ever obtained of the atmospheric escape phenomenon, a process capable of profoundly transforming a planet over time. The results are published in Nature Communications.
A member of the ultra-hot Jupiter family, WASP-121b is a massive gas giant that orbits so close to its star that its revolution lasts only 30 hours. The star's intense radiation heats its atmosphere to several thousand degrees, allowing light gases like hydrogen and helium to escape into space. Over millions of years, this slow atmospheric escape can alter the planet's size, composition, and future evolution.
Read More: Université de Genève
