A team of planetary scientists, including Michael Line, an associate professor at Arizona State University, has detected carbon dioxide in the atmosphere of a gas giant exoplanet with the James Webb Space Telescope (JWST).
The discovery demonstrates JWST’s long-awaited capabilities to observe the atmospheres of planets outside our solar system, revealing their composition and formation history. These results open the door to the possibility of learning more about the composition of small rocky planets that are thought to also contain carbon dioxide in their atmospheres.
The results of their findings have been accepted into Nature, titled “Identification of Carbon Dioxide in an Exoplanet Atmosphere.” This is the first accepted publication detailing exoplanet observations with JWST.
The gas giant exoplanet WASP-39 b was discovered in 2011 and orbits a star similar to our sun but 700 light years away. It has a mass approximately that of Saturn and it takes only four days to complete one orbit of its star, making it extremely hot, around 1,400 degrees Celsius. WASP-39b and other transiting exoplanets will allow researchers to examine the atmospheres of these worlds. A transit occurs when a planet passes between a star and the observer causing a slight attenuation of starlight.
For the study, Line, who is an associate professor in the School of Earth and Space Exploration, and the team used JWST’s near-infrared spectrograph (NIRSpec) to make the observations of the planet in different wavelengths, or colors, of light as it passes in front of its host star. These observations, also known as the transit spectrum, allowed the research team to determine exactly what the planet’s atmosphere is made up of.
“I felt like a kid in a candy store when I first saw this spectrum. The fact that we can see unambiguous bumps and ripples – point to them and say, ‘Hey, this is carbon dioxide, hey, it’s water vapor, wow, here’s that other bump and I don’t know what it is!” – suggests huge potential for discovery in worlds beyond our solar system. It’s really a game-changer,” Line said.
Understanding the composition of a planet’s atmosphere is important because it tells us something about the origin of the planet and how it evolved.
“Carbon dioxide molecules are sensitive tracers of the history of planet formation,” Line said. “By measuring this characteristic of carbon dioxide, we can determine how much solid (carbon and oxygen rich ices) versus how much gaseous matter (hydrogen and helium) was used to form this gas giant planet. Over the next decade, JWST will perform this measurement for a variety of planets, providing insight into the details of planet formation and the uniqueness of our own solar system.
The NIRSpec prism sighting of WASP-39b is just part of a larger investigation that includes observations of this planet using several instruments aboard the JWST, as well as observations of two others transiting planets. The survey, part of the Early Release Science program, was designed to provide the exoplanet research community with robust JWST data as soon as possible.
“The goal is to quickly analyze Early Release Science observations and develop open-source tools that the scientific community can use,” said study co-author Vivien Parmentier of the University of Oxford. “This allows for contributions from around the world and ensures that the best possible science will come out of the next few decades of observations.”
Line, along with NASA Hubble postdoctoral fellow Luis Welbanks and graduate student Lindsey Wiser, both in the School of Earth and Space Exploration, lead theoretical interpretations of data from the Early Release Science program .
“This is a once-in-a-lifetime opportunity,” Welbanks said. “For the first time in the history of the field, hundreds of people around the world are working together to learn as much as possible from these valuable observations.”
“This is just the beginning. We have many more datasets to analyze from this program – and several others – over the coming months and years,” Line said. figure out in my head that we are finally getting data from JWST. I thought I would have seen this data as a graduate student ten years ago. The wait was worth it.”
ASU press contact:
Kim Baptista, 707-479-0311, [email protected]
About Arizona State University
Arizona State University has developed a new model for American Research University, creating an institution that is committed to access, excellence, and impact. ASU is measured by those it includes, not by those it excludes. As the prototype of a new American university, ASU pursues research that contributes to the public good, and ASU bears a major responsibility for the economic, social, and cultural vitality of the communities around it.