Using NASA’s James Webb Space Telescope, scientists may have identified atmospheric gases on 55 Cancri e, a super-hot, rocky exoplanet. This discovery could represent the most definitive evidence of an atmosphere on any rocky planet outside our solar system. Credit: SciTechDaily.com
Researchers think they may have finally caught a glimpse of a volatile-rich atmosphere surrounding a rocky planet. Light emitted by the hot, highly-irradiated55 Cancri e shows compelling evidence for an atmosphere, probably rich in carbon dioxide or carbon monoxide, which may be bubbling from a vast ocean of lava covering the planet’s surface.This artist’s concept shows what the exoplanet 55 Cancri e could look like.
When the planet is next to the star, the mid-infrared light emitted by both the star and the dayside of the planet reaches the telescope, and the system appears brighter. When the planet is behind the star, the light emitted by the planet is blocked and only the starlight reaches the telescope, causing the apparent brightness to decrease.
By subtracting the brightness during the secondary eclipse , when the planet is behind the star , from the brightness when the planet is right beside the star , the team was able to calculate the amount of various wavelengths of infrared light coming from the dayside of the planet.A thermal emission spectrum captured by Webb’s NIRCam in November 2022, and MIRI in March 2023, shows the brightness of different wavelengths of infrared light emitted by the super-Earth exoplanet 55 Cancri e.
Credit: NASA, ESA, CSA, Joseph Olmsted , Renyu Hu , Aaron Bello-Arufe , Michael Zhang , Mantas Zilinskas The first indication that 55 Cancri e could have a substantial atmosphere came from temperature measurements based on its thermal emission , or heat energy given off in the form of infrared light.
“We’ve spent the last ten years modeling different scenarios, trying to imagine what this world might look like,” said co-author Yamila Miguel from the Leiden Observatory and the Netherlands Institute for Space Research . “Finally getting some confirmation of our work is priceless!”The team thinks that the gases blanketing 55 Cancri e would be bubbling out from the interior, rather than being present ever since the planet formed.