June 24, 2026
Astronomers have unveiled the discovery of one of the most extreme exoplanets ever found in the universe—a “giant roasted planet” that endures a catastrophic temperature spike of 610°C (approximately 1,100°F) as it makes its closest approach to its parent star . This extraordinary world, designated HD 80606 b, is a gas giant roughly four times the mass of Jupiter and is located about 217 light-years from Earth . What makes this planet truly unique is not just its immense size, but its highly unusual and brutal cosmic dance: it follows a sharply elongated, eccentric 111-day orbit around a star remarkably similar to our own Sun . This extreme orbit is the engine of its dramatic transformation, creating a completely different beast of a planet.
As it follows its egg-shaped path, HD 80606 b takes months to travel far out into the cold of space before plunging back in a blistering flyby, at which point its atmosphere is roasted in a way that has never been observed in such detail before. Using NASA’s James Webb Space Telescope, researchers were able to capture the planet before, during, and after this closest passage—known as periastron—and discovered that its temperature skyrockets by the equivalent of 610°C in a relatively short period . This rapid and intense heating is so extreme that it causes the planet’s atmospheric chemistry to change in real time, altering chemical signatures and cloud formations as the world is essentially cooked by its star .
The discovery has been heralded as a major leap forward in exoplanetary science, providing an unprecedented glimpse into the dynamic processes that govern these distant worlds. The data was collected using Webb’s Mid-Infrared Instrument (MIRI) during a carefully planned observation that took years to coordinate, due to the planet’s long orbit and the telescope’s observational constraints . “Hot Jupiters are already considered some of the most extreme exoplanets we know of, but even among that population, HD 80606 b is one of the most extreme,” said Tiffany Kataria, the study’s principal investigator at NASA’s Jet Propulsion Laboratory in Southern California .
“We typically think of hot Jupiters as hot gas giants sitting right next to their stars, but this planet’s highly eccentric orbit creates a completely different beast.” Her statement underscores just how exceptional this discovery is, as it challenges the conventional understanding of these hellish worlds. The planet had previously been dubbed the “roasted exoplanet” in NASA’s popular science series, a fitting moniker given the violent swings in temperature it endures . The observation campaign was highly efficient because the planet’s unusual orbit allows for the collection of data under varying conditions within just a few hours, offering a rare, real-time laboratory for studying atmospheric physics under extreme stress .
The scientific implications of this finding are profound, as the James Webb Space Telescope is now building on the legacy of its predecessor, the now-retired Spitzer Space Telescope. While Spitzer laid the groundwork for observing HD 80606 b, Webb’s advanced capabilities are allowing astronomers to drill down into specific details that were previously impossible to detect. “Spitzer did amazing work on this exoplanet, and now Webb is building on that legacy by enabling us to drill down to distinguish specific chemical signatures like methane and carbon dioxide, which is just amazing progress,” said Ryan Challener, a co-author of the study and research associate at the Cornell Center for Astrophysics and Planetary Science .
By using spectroscopy—a technique that breaks light into its component colors to reveal a planet’s chemical makeup, temperature, and motion—the team observed a dramatic shift in the planet’s chemical composition as it heated up . The ability to track molecules such as methane and carbon dioxide in real-time as the temperature changes by hundreds of degrees is a testament to Webb’s power and a crucial step forward in understanding planetary climates. “Webb has shown that the planet’s increase in temperature was even more extreme than we anticipated based on Spitzer data,” added Kataria, highlighting that the new observations surpassed even the most optimistic predictions .
Furthermore, this research is not just an isolated study of a single bizarre planet; it serves as a powerful template for understanding other worlds. The extreme conditions on HD 80606 b are being used as a key to unlock the mysteries of other hot Jupiters and more conventional exoplanets. “Observing a planet like HD 80606 b is actually very efficient because its unusual orbit, with the corresponding swings in temperature and chemical composition, allow us to gather data under varying conditions in just hours and apply those findings to other hot Jupiters or more conventional exoplanets,” explained Laura C. Mayorga, a co-investigator on the study and an exoplanet astronomer at the Johns Hopkins Applied Physics Laboratory .
This ability to generalize findings from such an extreme environment means that studying this “roasted” planet can help refine models for planetary climate and weather systems across the galaxy. The research, which was presented on Tuesday at the 248th meeting of the American Astronomical Society in Pasadena, California, confirms that we have only scratched the surface of what this dataset can reveal . As Challener noted, “There’s so much to learn from this one dataset here—we really are just getting started deciphering what Webb has to tell us” .
