The James Webb confirms its first exoplanet: it is the size of Earth and twice as hot

The capabilities of the James Webb Space Telescope continue to bear fruit. Now the existence of its first exoplanet has been confirmed, which is almost the same size as Earth, is rocky and is 41 light years from our planet.

classified as LHS 475bthe existence of this exoplanet was suggested by data from NASA’s TESS satellite, so the researchers decided to observe the object with James Webb, whose near-infrared spectrograph clearly captured that it was a planet outside the solar system. .

The scientific team was led by Kevin Stevenson and Jacob Lustig-Yaeger of the Johns Hopkins University Applied Physics Laboratory (USA), and the results were presented at the meeting of the American Astronomical Society.

LHS 475 b is 99% the diameter of Earth and is relatively close, just 41 light years awayin the constellation Octans.

“There is no doubt that the planet is there. Webb’s pristine data validates this,” said Lustig-Yaeger, quoted in a statement from the European Space Agency (ESA).

“These first observational results of a rocky, Earth-sized planet open the door to many future possibilities for studying” their atmospheres with Webb, said Mark Clampin, director of NASA’s Division of Astrophysics.

Of all the telescopes in operation, only Webb is capable of characterizing the atmospheres of Earth-sized exoplanets, so the team tried to assess it by analyzing its transmission spectrum.

The telescope is “so sensitive that it can easily detect a number of molecules, but we cannot yet draw any definitive conclusions about the planet’s atmosphere,” Lustig-Yaeger explained.

Although the team cannot conclude what is present, they can say what is not, and they rule out the existence of some thick methane-dominated atmospheres, similar to that of Saturn’s moon Titan.

Although the planet may not have an atmosphere, there are some atmospheric compositions that have not been ruled out, such as one of pure carbon dioxide.

“Counterintuitively, a 100% carbon dioxide atmosphere is much more compact and difficult to detect,” Lustig-Yaeger said.

So the team needs even more precise measurements to distinguish an atmosphere of pure carbon dioxide from no atmosphere at all. The researchers are scheduled to obtain additional spectra with new observations this summer.

Webb also revealed that the planet is a few hundred degrees warmer than Earth, so if clouds are detected, it could lead researchers to conclude that it is more like Venus, that it has a carbon dioxide atmosphere and is perpetually shrouded in dense clouds.

The researchers also confirmed that the planet completes one orbit in just two daysinformation that was revealed almost instantly by Webb’s precise light curve.

Although LHS 475 b is closer to its star than any other planet in the solar system, its red dwarf star is less than half the temperature of the Sun, so researchers project it could still harbor an atmosphere.

The researchers’ findings have opened up the possibility of locating Earth-size planets orbiting smaller red dwarf stars and also underscore “the precision of James Webb’s instruments,” Stevenson said.

For Lustig-Yager, thanks to James Webb, “rocky exoplanets are the new frontier.”

With information from EFE.