With the first definitive discovery of carbon dioxide in a planetary atmosphere outside our solar system, Webb ushers in a new era of exoplanet research.
According to NASA's James Webb Space Telescope, the atmosphere of a planet outside our solar system has the first conclusive evidence of carbon dioxide in its atmosphere. This observation of a gas giant planet orbiting a Sun-like star 700 light-years from Earth sheds light on its formation and evolution. The discovery, accepted for publication in Nature, provides evidence that Webb may one day be able to detect and measure carbon dioxide in the thinner atmospheres of smaller, rocky planets.
WASP-39 b is a hot gas giant with a diameter 1,3 times that of Jupiter and a mass about a quarter of Jupiter (roughly the same as Saturn). Its high temperature contributes to some of its extreme bloating (about 1.600 degrees Fahrenheit or 900 degrees Celsius).
Unlike the cooler, more compact gas giants in our Solar System, WASP-39 b is very close to its star's orbit, only about one-eighth the distance between the Sun and Mercury. It makes one lap in just over four Earth days.
Announcing in 2011, it was the passing in front of its host star, causing a modest, periodic dimming of the star's brightness that led to the discovery of the planet.
According to previous work from telescopes such as NASA's Hubble and Spitzer satellite telescopes, the planet's atmosphere contains water vapor, sodium and potassium. The existence of carbon dioxide on this planet is now confirmed, thanks to Webb's unrivaled infrared sensitivity.
Researchers can take advantage of transiting planets like WASP-39 b, whose orbits we've seen from the edge rather than from above, to study planetary atmospheres.
Some of the starlight is partially obscured by the planet during a transit (causing total dimming), and some is transmitted through the planet's atmosphere.
Because different gases absorb different color combinations, researchers can determine the precise composition of an atmosphere by analyzing very small changes in the brightness of transmitted light across a wavelength spectrum.
WASP-39 b is a good target for transmission spectroscopy because of its inflated atmosphere and regular transitions.
First Accurate Detection of Carbon Dioxide
For WASP-39 b observations, the research team used Webb's Near Infrared Spectrograph (NIRSpec). The first definitive, in-depth evidence of carbon dioxide ever found on an exoplanet is offered by a small peak between 4,1 and 4,6 microns in the resulting spectrum of the exoplanet's atmosphere.
Zafar Rustamkulov, a PhD student at Johns Hopkins University and a member of the JWST Transit Exoplanet Community Early Release Science team that carried out this analysis, said, “As soon as the data came onto my screen, the enormous carbon dioxide feature grabbed me. “Crossing a very important threshold in exoplanet research was a special occasion.
Never before had an observatory recorded such small changes in the brightness of so many different colors in an exoplanet transmission spectrum between 3 and 5.5 micron wavelengths. Access to this part of the spectrum is essential to determine the abundance of gases such as water, methane and carbon dioxide believed to exist in various types of exoplanets.
Leading the research is Natalie Batalha of the University of California, Santa Cruz. “Detection of such a clear signal of carbon dioxide in WASP-39 b bodes well for identifying atmospheres on smaller, terrestrial-sized planets,” she said.
Understanding a planet's atmosphere is very important because it contains information about the formation and evolution of the planet. According to Mike Line of Arizona State University, another member of the research team, "Carbon dioxide molecules are sensitive trackers of the planet formation story." By examining this feature of carbon dioxide, we can tell how much solid and how much gaseous material was used to build this gas giant planet.
JWST will take this measurement for a number of planets over the next decade, shedding light on the characteristics of planet formation and the characteristics of our own solar system.
Early Release Science
This NIRSpec prism observation of WASP-39 b is just a small part of a larger survey that includes observations of two additional transiting planets and studies of the planet using several Webb equipment.
The query, a component of the Early Release Science initiative, was created with the aim of giving Webb data to the exoplanet research community as soon as possible.
According to co-researcher Vivien Parmentier of the University of Oxford, “the goal is to rapidly evaluate Early Release Science findings and create open-source tools for the scientific community to use.”
This allows for contributions from all over the world and ensures that the next decade of observations will produce the greatest possible science.
"NASA's open science guidelines are embedded in our Early Release Science study and encourage an inclusive, transparent and collaborative scientific approach," said Natasha Batalha, co-author on the research, of NASA's Ames Research Center.
The world's best space scientific observatory is the James Webb Space Telescope. Webb will explore the mysterious architecture of the cosmos, its origins and our role in it, as well as looking beyond our solar system to distant planets orbiting other stars.
A multinational project called Webb is run by NASA in conjunction with the Canadian Space Agency and the European Space Agency.