The James Webb telescope detects carbon dioxide in the atmosphere of an exoplanet

Aug. 26 () –

The Space Telescope james webb of NASA/ESA/CSA has found definitive evidence of presence of carbon dioxide in the atmosphere of a gas giant planet –WASP-39 b– orbiting a Sun-like star 700 light-years away.

As reported by the European Space Agency, this finding provides important information about the composition and formation of the planetand is indicative of Webb’s ability to also detect and measure carbon dioxide in the thinner atmospheres of smaller rocky planets.

WASP-39 b is a hot gas giant with a mass about a quarter that of Jupiter (about the same as Saturn) and a diameter 1.3 times that of Jupiter. Its extreme swelling is partly related to its high temperature (around 900°C).

Unlike the cooler, more compact gas giants in the Solar System, WASP-39 b orbits very close to its host star, only about one-eighth the distance between the Sun and Mercury, completing one circuit in just over four days. terrestrial.

The planet’s discovery, reported in 2011, was based on ground-based detections of the subtle and periodic dimming of its host star’s light as the planet transits or passes in front of the star.

Transiting planets like WASP-39 b, whose orbits are viewed edge-on rather than from above, may provide researchers with ideal opportunities to probe planetary atmospheres, according to ESA.

In this sense, he has pointed out that, during a transit, part of the starlight is eclipsed by the planet completely (causing the general dimming) and part is transmitted through the planet’s atmosphere. “The atmosphere filters some colors more than others, depending on factors like what it’s made of, how thick it is, and whether or not there are clouds.“, has added.

Because different gases absorb different combinations of colors, researchers can analyze tiny differences in the brightness of transmitted light across a spectrum of wavelengths and thus determine exactly what an atmosphere is made of.

“As soon as the data appeared on my screen, I was struck by the huge carbon dioxide feature“, explained Zafar Rustamkulov, a graduate student at Johns Hopkins University in the United States and a member of the transiting exoplanets team. “It was a special moment, crossing an important threshold in exoplanet sciences,” he declared.

Natalie Batalha, director of the research team, for her part, has indicated that, “The detection of such a clear signal of carbon dioxide in WASP-39 b bodes well for the detection of atmospheres on smaller Earth-sized planets.”.