“Super-Jupiter” Study Upends Science’s Understanding of Massive Planets
A new study, coauthored by University of Virginia astronomer Yifan Zhou, reveals extraordinary weather on a planet researchers are calling a “super-Jupiter,” challenging assumptions that massive exoplanets resemble our own Solar System’s gas giants.
Jupiter has been the primary template for understanding giant planets for decades, but the study’s findings not only reshape astronomers’ expectations for what giant exoplanets look like but also provide a powerful new framework for interpreting atmospheric behavior on massive, directly imaged planets beyond our Solar System.
The study focuses on VHS 1256 b, one of the most variable objects with planetary mass ever observed in the galaxy. According to the research, made possible by the Hubble Space Telescope and the James Webb Space Telescope, the planet’s near-infrared brightness swings by nearly 40 percent, the largest difference recorded for any object of its kind.
Using a sophisticated atmospheric circulation model, the team demonstrated that VHS 1256 b’s dramatic variability and spectral signatures can be explained by massive, global-scale dust storms, unlike Jupiter whose stable bands are evidence of a less turbulent environment. Instead, the planet’s atmosphere appears dominated by planetary-scale waves and thick silicate clouds that generate enormous, fast-moving storms.
Because VHS 1256 b is significantly hotter than Jupiter, the dynamics of its clouds and atmosphere differ dramatically. The researchers argue that temperature, rather than mass alone, plays a critical role in shaping whether a giant planet develops orderly bands or chaotic, storm-driven weather.
Zhou’s earlier work helped characterize VHS 1256 b as one of the highest-variability substellar objects known, establishing a baseline that made this new modeling effort possible. He and his team are currently using the James Webb Space Telescope to monitor the weather on the planet.
The study appears in Science Advances.
