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The James Webb Space Telescope could add another cosmic achievement to its list: The Space Observatory has been used to confirm the existence of an exoplanet for the first time.
The celestial body, known as LHS 475 b and located outside our solar system, is almost exactly the size of Earth. The rocky world is 41 light-years away in the constellation Octans.
Previous data collected by NASA’s Transiting Exoplanet Survey Satellite, or TESS, has suggested that the planet could exist.
A group of researchers, headed by staff astronomer Kevin Stevenson and postdoctoral fellow Jacob Lustig-Yaeger at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, observed the target using Webb. They watched the waning of starlight as the planet passed in front of its host star, known as a transit, and observed two transits occurring.
“There is no doubt that the planet is there. Lustig-Yaeger said Webb’s pristine data confirmed that. in a statement.
The planet’s discovery was announced Wednesday at the 241st meeting of the American Astronomical Society in Seattle.
“The fact that it’s also a small, rocky planet is impressive for the observatory,” says Stevenson.
Webb is the only telescope capable of depicting the atmospheres of Earth-sized exoplanets. The team used Webb to analyze the planet across multiple wavelengths of light to see if it had an atmosphere. Currently, the team cannot draw any firm conclusions, but the telescope’s sensitivity has been obtained on a wide range of molecules present.
“There are several terrestrial atmospheres that we can rule out,” says Lustig-Yaeger. “It cannot have a dense atmosphere of mostly methane, similar to that of Saturn’s moon Titan.”
Astronomers will have another chance to observe the planet again this summer and conduct follow-up analysis of the potential presence of an atmosphere.
Webb’s discovery also revealed that the planet is several hundred degrees warmer than our own. If the researchers detect any clouds on LHS 475 b, it could be more like Venus – considered Earth’s hotter twin with a carbon dioxide atmosphere.
“We are at the forefront of studying small rocky exoplanets,” said Lustig-Yaeger. “We’ve barely begun to explore what the surface of their atmosphere might be like.”
The planet completes an orbit around its red dwarf host star every 2 Earth days. Given that the star is less than half the temperature of our sun, it is possible that the planet still maintains an atmosphere despite its proximity to the star.
The researchers believe their discovery will be just the first of many in Webb’s future.
“These first observations from a rocky, Earth-sized planet open the door to many possibilities,” said Mark Clampin, Director of the Astrophysics Division at NASA Headquarters. in the future to study the atmosphere of the rocky planet with Webb. “Webb is bringing us closer and closer to a new understanding of Earth-like worlds beyond the Solar System, and the mission is just beginning.”
Many of Webb’s observations were shared at Wednesday’s meeting, including previously unseen images of a dusty disk swirling around a nearby red dwarf star.
The telescope’s image marks the first time such a disk has been captured in these infrared wavelengths of light invisible to the human eye.
The dusty disk around the star, dubbed AU Mic, represents a remnant of planet formation. When small, solid objects called planets – a planet in the process of formation – collide, they leave a large ring of dust around the star and form a crumbling disk.
“A disk of debris is continuously replenished by the collisions of planets. Kellen Lawson, lead author of the study, postdoctoral fellow at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and member of the team that studied the AU Mic, said: By studying it, we get a unique window into the recent dynamics history of this system.” .
Webb’s ability allows astronomers to see the region close to the star. Their observations and data can provide insights that help search for giant planets that form wide orbits in planetary systems, unlike Jupiter and Saturn in their own solar systems. ta.
The AU Mic disk is located 32 light-years away in the constellation Microscopium. According to the researchers, the star is about 23 million years old, so planet formation around the star has stopped – as that process usually takes less than 10 million years. Other telescopes have discovered two planets orbiting the star.
“This system is one of the very few examples of a young star, with known exoplanets and a debris disk close enough and bright enough to study as a whole using powerful instruments. Webb’s unique power,” said study co-author Josh Schlieder, the project’s principal investigator. observatory program at NASA’s Goddard Space Flight Center.
The Webb telescope was also used to observe the interior of NGC 346, a star-forming region located in a neighboring dwarf galaxy called the Small Magellanic Cloud.
About 2 billion up to 3 billion years after the big bang that created the universe, galaxies were filled with fireworks that formed stars. This climax of star formation is known as “cosmic noon”.
“A galaxy at cosmic noon would not have an NGC 346, like the Small Magellanic Cloud; it’s going to be in the thousands,” said Margaret Meixner, an astronomer at the Association for University Space Research and the team’s principal investigator. in a statement.
“Even if NGC 346 is currently the only and only massive star cluster that is violently forming in its galaxy, it still provides us with an excellent opportunity to probe the conditions that occurred in the early morning hours. noon of the universe.”
Observing how stars form in this galaxy allows astronomers to compare star formation in our own Milky Way.
In Webb’s new image, forming stars can be seen pulling ribbon-like gas and dust from the surrounding molecular cloud. This material fosters the formation of stars, and eventually planets.
Co-investigator Guido De Marchi, a member of the European Space Agency’s space science department, said: “We are seeing the building blocks, not only of stars, but potentially also of the planets. “And because the Small Magellanic Cloud has an environment similar to that of galaxies at the midday of the universe, it is possible that rocky planets formed earlier in the history of the Universe than we know. think.”
