JWST Captures Atmospheric Changes as Exoplanet Gets Roasted by Its Star
Summary: JWST observed HD 80606 b through its 111-day eccentric orbit, capturing for the first time detailed atmospheric changes as temperatures surge ~1,100°F during closest approach to its star.
The James Webb Space Telescope has conducted continuous observations of exoplanet HD 80606 b, capturing for the first time in detail how a planet's atmosphere responds as it is rapidly heated during close approach to its host star. HD 80606 b is a hot Jupiter on a highly eccentric orbit with a period of approximately 111 days. At periastron — the point of closest approach — the planet's surface temperature surges by roughly 1,100°F (about 600°C) in a matter of hours before gradually cooling as it recedes from the star.
The research team leveraged JWST's infrared capabilities to observe HD 80606 b before, during, and after its periastron passage, producing a complete record of its atmosphere transitioning from a relatively cool state through rapid heating and into a slow cooling phase. This marks the first time astronomers have tracked the dynamic atmospheric changes of an exoplanet with such temporal resolution, providing valuable data for understanding how planetary atmospheres physically and chemically respond under extreme stellar irradiation.
Located approximately 190 light-years from Earth, HD 80606 b orbits a Sun-like star. The planet's extreme orbital geometry is believed to result from gravitational interactions with a stellar companion, making it a natural laboratory for studying how tidal forces shape planetary orbital evolution. NASA has published the findings, and analysis of JWST's observation data is ongoing.