Originally posted by the European Space Agency on January 11, 2022. Edits by EarthSky.
Webb discovers its 1st exoplanet
Extra information from the American Astronomical Society meeting, occurring this week in Seattle. Astronomers stated yesterday (January 11, 2023) that – for the primary time – they’ve confirmed an exoplanet, a planet orbiting a distant star, utilizing the Webb space telescope. The mighty telescope went into orbit and commenced working in 2022. The planet has been labeled LHS 475 b. It’s regarded as rocky and Earth-sized (99% of Earth’s diameter). The planet whips round its star in simply 2 days, far sooner than any planet in our solar system. It’s solely 41 light-years away, within the route of the south polar constellation Octans the Octant.
Kevin Stevenson and Jacob Lustig-Yaeger, each of the Johns Hopkins College Utilized Physics Laboratory, led the analysis group. The group selected to look at this goal with Webb after rigorously reviewing information from NASA’s Transiting Exoplanet Survey Satellite tv for pc (TESS) which hinted on the planet’s existence. Webb’s Close to-Infrared Spectrograph (NIRSpec) captured the planet simply and clearly with solely two transit observations. Lustig-Yaeger stated in a statement:
There isn’t a query that the planet is there. Webb’s pristine information validate it. The truth that it’s also a small, rocky planet is spectacular for the observatory.
Mark Clampin, Astrophysics Division director at NASA Headquarters in Washington, agreed, saying:
These first observational outcomes from an Earth-sized, rocky planet open the door to many future potentialities for learning rocky planet atmospheres with Webb … And the mission is simply simply getting began.
What makes Webb so highly effective
Amongst all working telescopes, solely Webb is able to characterizing the atmospheres of Earth-sized exoplanets. The group tried to evaluate what’s within the planet’s environment by analyzing its transmission spectrum. Though the info present that that is an Earth-sized terrestrial planet, they don’t but know if it has an environment. Erin May, additionally of Johns Hopkins, said:
The observatory’s information are lovely. The telescope is so delicate that it may simply detect a spread of molecules. However we will’t but draw any definitive conclusions concerning the planet’s environment.
Though the group can’t conclude what’s current, they’ll undoubtedly say what is just not current. Lustig-Yaeger said:
There are some terrestrial-type atmospheres that we will rule out. It could possibly’t have a thick methane-dominated environment, just like that of Saturn’s moon Titan.
The group additionally notes that whereas it’s doable the planet has no environment, there are some atmospheric compositions that haven’t been dominated out, resembling a pure carbon dioxide environment. Lustig-Yaeger explained:
Counterintuitively, a 100% carbon dioxide environment is a lot extra compact that it turns into very difficult to detect.
Much more exact measurements are required for the group to tell apart a pure carbon dioxide environment from no environment in any respect. The researchers are scheduled to acquire extra spectra with additional observations this summer season.
Perhaps extra like Venus?
Webb additionally revealed that the planet is a couple of hundred levels hotter than Earth, so if clouds are detected it could lead the researchers to conclude that the planet is extra like Venus, which has a carbon dioxide environment and is perpetually shrouded in thick cloud. Lustig-Yaeger said:
We’re on the forefront of learning small, rocky exoplanets. We’ve got barely begun scratching the floor of what their atmospheres is perhaps like.
The researchers additionally confirmed that the planet completes an orbit in simply two days, info that was nearly instantaneously revealed by Webb’s exact light curve. Though LHS 475 b is nearer to its star than any planet in our solar system, its crimson dwarf star is lower than half the temperature of our sun, so the researchers challenge it nonetheless might help an environment.
The researchers’ findings have opened up the potential of pinpointing Earth-sized planets orbiting smaller red dwarf stars. Lustig-Yaeger agreed, saying:
This rocky planet affirmation highlights the precision of the mission’s devices. And it is just the primary of many discoveries that it’ll make.
With this telescope, rocky exoplanets are the brand new frontier.
Backside line: Webb discovers its first exoplanet! And – talking this week on the American Astronomical Society assembly in Seattle – astronomers are excited.
