Fomalhaut b

For the second star in the Fomalhaut system, see TW Piscis Austrini.
Fomalhaut b
Fomalhaut b as observed from 2004 to 2014. Previously thought to be an exoplanet, it is now known to be an expanding dust cloud.
Discovery
Discovered byKalas et al.[1]
Discovery siteHubble Space Telescope
Discovery dateNovember 13, 2008
Direct imaging
Orbital characteristics
StarFomalhaut

Fomalhaut b, formally named Dagon (/ˈdeɪɡən/),[2] is a former candidate planet observed near the A-type main-sequence star Fomalhaut, approximately 25 light-years away in the constellation of Piscis Austrinus. The object's discovery was initially announced in 2008 and confirmed in 2012 via images taken with the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope. Under the working hypothesis that the object was a planet, it was reported in January 2013[3][4] that it had a highly elliptical orbit with a period of 1,700 Earth years.[5] The object was one of those selected by the International Astronomical Union as part of NameExoWorlds, their public process for giving proper names to exoplanets.[6][7] The process involved public nomination and voting for the new name.[8] In December 2015, the IAU announced the winning name was Dagon.[9][10][11]

The planetary hypothesis has since fallen out of favor; more gathered data suggested a dust or debris cloud is far more likely, and the object was placed on an escape trajectory.[12] In 2023, a team of researchers used the James Webb Space Telescope's MIRI to probe the complex dust environment around the Fomalhaut. They discovered a new intermediate dust belt that might be shepherded by an unseen planet and suggested that the blob, Fomalhaut b, could have originated in this belt. The recent research of the Fomalhaut system used the JWST's NIRCam equipped with coronagraphs to probe the complex dust ring in different wavelengths of infrared light. The absence of detection in certain wavelengths support the idea that Fomalhaut b is not a massive planet but rather a dust cloud resulting from a collision among planetesimals.[13][14]

  1. ^ Cite error: The named reference Kalas2008 was invoked but never defined (see the help page).
  2. ^ "Dagon". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
  3. ^ Cite error: The named reference NASA-20130108a was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference NASA-20130108b was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Kalas2013 was invoked but never defined (see the help page).
  6. ^ NameExoWorlds: An IAU Worldwide Contest to Name Exoplanets and their Host Stars. IAU.org. 9 July 2014
  7. ^ NameExoWorlds Archived 2018-06-25 at the Wayback Machine.
  8. ^ NameExoWorlds Archived 2015-08-15 at the Wayback Machine.
  9. ^ Final Results of NameExoWorlds Public Vote Released, International Astronomical Union, 15 December 2015.
  10. ^ "SCSU planetarium names an exoplanet". St. Cloud Times. Retrieved 2015-12-29.
  11. ^ "NameExoWorlds The Approved Names". Archived from the original on 2018-02-01. Retrieved 2016-09-10.
  12. ^ Cite error: The named reference PNAS-20200420 was invoked but never defined (see the help page).
  13. ^ Ygouf, Marie; Beichman, Charles; Llop-Sayson, Jorge; Bryden, Geoffrey; Leisenring, Jarron; Gaspar, Andras; Krist, John; Rieke, Marcia; Rieke, George (2024). "Searching for Planets Orbiting Fomalhaut with JWST/NIRCam". The Astronomical Journal. 167 (1): 26. arXiv:2310.15028. Bibcode:2024AJ....167...26Y. doi:10.3847/1538-3881/ad08c8.
  14. ^ Gough, Evan; Today, Universe. "JWST searches for planets in the Fomalhaut system". phys.org. Retrieved 2024-03-18.