A whole new world! 41 light-years away is the small, rocky pl | Cosmos Astronomia® 🔭

A whole new world!

41 light-years away is the small, rocky planet LHS 475 b. At 99% of Earth’s diameter, it’s almost exactly the same size as our home world. This marks the first time researchers have used the Webb telescope to confirm an exoplanet.

NASA’s exoplanet-hunting TESS mission hinted at the planet’s existence, making it a target of interest for Webb. Webb’s NIRSpec instrument then captured the planet with just 2 transit observations.

Although Webb data tells us that LHS 475 b is a small rocky world, the existence and composition of its atmosphere is a mystery. The planet is a few hundred degrees warmer than Earth and very close to its star, completing an orbit in just 2 days. However, its red dwarf star is much cooler than our Sun, so scientists theorize an atmosphere is still possible. Additional follow-up observations are scheduled this summer. Learn more at the link in our bio!

Credits: Illustration - NASA, ESA, CSA, L. Hustak (STScI); Science - K. Stevenson, J. Lustig-Yaeger, E. May (Johns Hopkins University Applied Physics Laboratory), G. Fu (Johns Hopkins University), and S. Moran (University of Arizona)

Image descriptions:
1. Background illustration features a rocky planet and its small, bright star on a black background. Text reads: “First Exoplanet Confirmed with the Webb Telescope.”

2. Transit light curve of exoplanet LHS 475 b, with data from Webb’s NIRSpec instrument. Text reads: “41 light-years away is the small, rocky world LHS 475 b, which clocks in at 99% of Earth's diameter. It completes an orbit in just 2 days!” Below that is a graph showing the change in relative brightness of the star-planet system between 3-6 pm in Baltimore, MD on Aug. 31, 2022. The spectrum shows that the brightness of the system remains steady until the planet begins to transit the star. It decreases when the planet is directly in front of the star, then increases again when the planet is no longer blocking the star, at which point it levels out. Data is shown in purple circles. The line of best fit forms a U-shaped valley of low brightness labeled “Starlight blocked by the planet” at 5 p.m.