Astronomy:Kepler-421b

From HandWiki
Kepler-421b
Discovery
Discovery siteKepler telescope
Discovery date2014
Transit
Orbital characteristics
1.219 AU (182,400,000 km)
Orbital period704.1984 d
Inclination89.965
StarKepler-421
Physical characteristics
Mean radius4.16 R


Kepler-421b is an exoplanet that, as of July 2014,[1] has the longest known year of any transiting planet (704 days),[2] although not as long as the planets that have been directly imaged, or many of the planets found by the radial-velocity method, or as long as some transiting planet candidates which are listed as planets in the Extrasolar Planets Encyclopaedia (KIC 5010054 b etc.).[3] It is the first transiting-planet found near the snow-line.

Normally, at least three transits are required to confirm a planet. Due to very high signal to noise ratio, only two transits were sufficient to validate Kepler-421b to be a real planet without additional confirmation methods.

Kepler-421b is slightly larger than Uranus although its mass is not known.

References

  1. Kipping, D. M.; Torres, G.; Buchhave, L. A.; Kenyon, S. J.; Henze, C.; Isaacson, H.; Kolbl, R.; Marcy, G. W. et al. (2014), "Discovery of a Transiting Planet Near the Snow-Line", The Astrophysical Journal 795 (1): 25, doi:10.1088/0004-637X/795/1/25, Bibcode2014ApJ...795...25K 
  2. Johnson, Michele (July 21, 2014). "Astronomers Discover Transiting Exoplanet with Longest Known Year". NASA. http://www.nasa.gov/ames/kepler/transiting-exoplanet-with-longest-known-year. Retrieved July 25, 2014. 
  3. "The Extrasolar Planet Encyclopaedia — Catalog Listing". Extrasolar Planets Encyclopaedia. https://exoplanet.eu/catalog/?f=%22transit%22+IN+detection/. 

Further reading