LHS 475 b
Artist's rendering of LHS 475b
Discovery
Discovered byJames Webb Space Telescope
Discovery date2023
Transit
Orbital characteristics[1]
2.0291±0.0000 d
StarLHS 475
Physical characteristics[1]
Mean radius
0.99±0.05 R🜨
Mass0.91±0.19 M🜨
Temperature586 K (313 °C, 595 °F)

LHS 475 b is a terrestrial planet orbiting the star LHS 475 which is about 40.7 light years away, in the constellation of Octans.[2][3] It was the first extrasolar planet to be confirmed by the James Webb Space Telescope.[4] It completes an orbit every 2 days and is 99% the diameter of Earth. It is also one of the most similar-to-Earth exoplanets discovered, in terms of radius.[5]

Physical characteristics

LHS 475 b has a radius equivalent to 99% of the Earth's radius and a mass equivalent to 91.4% of the Earth's mass.[6][7] It completes an orbit around its star in about 2 days and is most likely tidally locked.[7]

Atmosphere

It is not yet known whether LHS 475 b has an atmosphere. It is possible that, in fact, it does not, but there are some atmospheric compositions that have not been ruled out, such as an atmosphere made up of 100% carbon dioxide, which is difficult to detect.[6][8] As it is very hot, with a temperature of 313 °C, if clouds are detected on its surface, this could suggest that LHS 475 b is similar to Venus, which has an atmosphere made up of carbon dioxide surrounded by thick clouds.[6]

Discovery and observation

The Transiting Exoplanet Survey Satellite (TESS) telescope indicated the existence of an exoplanet around the star LHS 475 through transit information.[6][9]

Transmission spectrum of LHS 475 b from NIRSpec.

On August 31, 2022, the James Webb Space Telescope's NIRSpec instrument captured the exoplanet with just two transit observations and observed its transmission spectrum. Confirmation of LHS 475 b by the James Webb Space Telescope was published on January 11, 2023.[10][11][12]

See also

References

  1. ^ a b "Open Exoplanet Catalogue - LHS 475 b".
  2. ^ "Exoplanet LHS 475 b and Its Star (Illustration)". WebbTelescope.org. Retrieved 2023-01-18.
  3. ^ Anderson, Natali (2023-01-12). "Webb Confirms Earth-Sized Planet around LHS 475 | Sci.News". Sci.News: Breaking Science News. Retrieved 2023-01-18.
  4. ^ Cowing, Keith (2023-01-12). "Webb Discovers LHS 475 b, An Earth-Sized, Rocky Planet". Astrobiology. Retrieved 2023-01-18.
  5. ^ Adkins, Jamie (2023-01-09). "NASA's Webb Confirms Its First Exoplanet". NASA. Retrieved 2023-01-18.
  6. ^ a b c d "NASA's Webb Confirms Its First Exoplanet - NASA". 2023-01-11. Retrieved February 22, 2023.
  7. ^ a b Martin, Pierre-Yves (2023). "Planet LHS 475 b". Extrasolar Planets Encyclopaedia. Retrieved February 22, 2023.
  8. ^ "James Webb Telescope finds its first exoplanet". NBC News. 2023-01-11. Retrieved February 22, 2023.
  9. ^ "LHS 475 b: Earth-Sized Exoplanet | Science Mission Directorate". science.nasa.gov. Retrieved February 22, 2023.
  10. ^ "James Webb Telescope finds its first exoplanet". NBC News. 2023-01-11. Retrieved February 22, 2023.
  11. ^ "How JWST confirmed its first exoplanet and opened a new frontier". The Planetary Society. Retrieved February 22, 2023.
  12. ^ "Exoplanet LHS 475 b (Transmission Spectrum)". Webb Space Telescope.
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