Astronomy:HD 219666 b

From HandWiki
Discovery
Discovery date2018
Transit
Orbital characteristics
0.06356 AU
Orbital period6.03607 d
StarHD 219666
Physical characteristics
Mean radius4.71 Earth radius
Mass16.6 M🜨
Physics1073 K


HD 219666b is a hot Neptune type exoplanet that orbits around the G-type main sequence star named HD 219666 (also known as TOI-118). It orbits the star at a distance of 0.06 AU with an orbital period of 6.03 days. The close orbit of the planet makes the temperature of the planet rise to 1073 Kelvin. The planet has a mass of 16.6 Earth masses with a radius of 4.71 Earth radii. It was discovered in 2018 using the transit method of exoplanet detection.[1][2]

HD 219666b has an atmosphere that is rich in water vapor but is significantly depleted in methane.[3]

References

  1. ↑ Martin, Pierre-Yves (2025). "Planet HD 219666 b" (in en). https://exoplanet.eu/catalog/hd_219666_b--6937/. 
  2. ↑ Esposito, M.; Armstrong, D. J.; Gandolfi, D.; Adibekyan, V.; Fridlund, M.; Santos, N. C.; Livingston, J. H.; Mena, E. Delgado et al. (2019-03-01). "HD 219666 b: a hot-Neptune from TESS Sector 1" (in en). Astronomy & Astrophysics 623: A165. doi:10.1051/0004-6361/201834853. ISSN 0004-6361. Bibcode2019A&A...623A.165E. https://www.aanda.org/articles/aa/full_html/2019/03/aa34853-18/aa34853-18.html. 
  3. ↑ Murphy, Matthew M.; Beatty, Thomas G.; Welbanks, Luis; Fu, Guangwei (May 2025). "HST Transmission Spectra of the Hot Neptune HD 219666 b: Detection of Water and the Challenge of Constraining Both Water and Methane" (in en). The Astronomical Journal 169 (6): 286. doi:10.3847/1538-3881/adc684. ISSN 1538-3881. Bibcode2025AJ....169..286M.