The 610-Degree Roast - Astronomers Witness an Exoplanets Extreme Sunburn
Summary: Using JWST, researchers captured an exoplanet before, during, and after periastron, discovering its temperature skyrockets by ~610°C during closest approach to its parent star.
According to CosmoScience, a research team led by Tiffany Kataria at NASA's Jet Propulsion Laboratory (JPL) has conducted an unprecedented continuous observation of the hot Jupiter exoplanet HD 80606 b using the James Webb Space Telescope's Mid-Infrared Instrument (MIRI). The team collected atmospheric data before, during, and after the planet's periastron -- its closest approach to its parent star.
The observations reveal that HD 80606 b's temperature skyrockets by approximately 610 degrees Celsius (about 1,100 degrees Fahrenheit) within just a few hours near periastron, making it one of the most dramatic planetary heating events ever recorded. This extreme temperature swing is driven by the planet's highly elliptical orbit, which causes the distance between the planet and its star to vary dramatically, resulting in a sharp increase in stellar radiation at closest approach.
This marks the first time astronomers have obtained a complete mid-infrared observation of an exoplanet bracketing its periastron passage, providing key insights into how orbital eccentricity shapes planetary atmospheric dynamics. HD 80606 b, located roughly 190 light-years from Earth in the constellation Ursa Major, has long attracted scientific interest precisely because of its unusually high orbital ellipticity. The new data offer a critical window into how planetary atmospheres respond under extreme orbital conditions.