The James Webb Space Telescope has confirmed the existence of its first exoplanet. It is almost Earth-sized, rocky, and 41 light-years from our planet.
The exoplanet, classified as LHS 475 b, was suggested by data from NASA’s TESS satellite, so the researchers decided to follow up with James Webb, whose near-infrared spectrograph clearly identified it as an extrasolar exoplanet. system.
The research team was led by Kevin Stevenson and Jacob Lustig-Yager from the Johns Hopkins University Applied Physics Laboratory (USA) and presented the results at a meeting of the American Astronomical Society.
LHS 475 b is 99% the diameter of Earth and is relatively nearby, just 41 light-years away, in the constellation Octanes.
It is several hundred degrees warmer on Earth
Webb also revealed that the planet is several hundred degrees warmer than Earth, so if clouds are found, researchers may conclude that it is more like Venus, that it has a carbon dioxide atmosphere and is permanently covered by thick clouds.
The researchers also confirmed that the planet completes one orbit in just two days, information 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 believe it could still have an atmosphere.
The researchers’ findings raise the possibility of finding Earth-sized planets orbiting small red dwarf stars, Stevenson said.
For Lustig-Jaeger, thanks to James Webb, “Rocky exoplanets are the new frontier.”
Now they are studying the planet’s atmosphere
“These first observational results of a rocky, Earth-sized planet open up many future possibilities for studying their atmospheres with space telescopes,” said Mark Clampin, director of NASA’s Astrophysics Division.
Of all the telescopes in operation, only Webb can characterize the atmospheres of Earth-sized exoplanets, so the team tried to evaluate the new exoplanet by analyzing its transmission spectrum.
The telescope is “so sensitive that it can easily detect a few molecules,” but they still cannot draw any definitive conclusions about the planet’s atmosphere. While the team can’t conclude what it is, they can say what it isn’t and rule out the existence of some thick methane-dominated atmospheres, similar to Saturn’s moon Titan.
Although the planet may not have an atmosphere, there are atmospheric compositions that cannot be ruled out, such as pure carbon dioxide. “Counterintuitively, a 100% carbon dioxide atmosphere is much more compact and difficult to detect,” Lustig-Jaeger said.
So the team needs even more precise measurements to distinguish pure carbon dioxide from the atmosphere. The researchers plan to obtain additional spectra with new observations this summer.
Source: El Diario