Fomalhaut b

Initial discovery by Hubble and the system around Fomalhaut The existence of a massive planet orbiting Fomalhaut was first inferred from Hubble observations published in 2005 that resolved the structure of Fomalhaut's massive, cold debris disk (or dust belt/ring). In May 2008, Paul Kalas, James Graham and their collaborators identified Fomalhaut b from Hubble/ACS images taken in 2004 and 2006 at visible wavelengths (i.e. 0.6 and 0.8 μm). NASA released the composite discovery photograph on November 13, 2008, coinciding with the publication of discovery by Kalas et al. in Science. Early follow-up observations and doubts In the discovery paper, These results invoked skepticism about Fomalhaut b's status as an extrasolar planet. Recovery and independent confirmation by Hubble On October 24, 2012, a team led by Thayne Currie at the University of Toronto announced the first independent recovery of Fomalhaut b and revived the claim that Fomalhaut b was a planet. although this is a non-technical term used in press material and does not appear in any peer-reviewed manuscript. Confirmation as a debris cloud Analyses of additional STIS data obtained in 2013 and 2014, published in 2020, found that Fomalhaut b is fading and expanding in size, a behavior that supports the interpretation of Fomalhaut b as a debris cloud from a collision between two asteroid-sized objects on an escape trajectory, rather than a planet. Observations by the James Webb Space Telescope in 2023 did not detect Fomalhaut b in the infrared, confirming its nature as a dust cloud and not a planet. == Physical characteristics ==

Fomalhaut b was hypothesized to be a gaseous, Jupiter like planet, the planet was disproven, and confirmed to be a dust cloud. == Other hypothesized planets ==

Based on the (now disproven) assumption that Fomalhaut b was a gaseous planet, the existence of additional planets closer to the star had been postulated. Fomalhaut b would be orbiting its host star at a wide separation, where forming massive planets is difficult. To explain its current location, Fomalhaut b would have had to be dynamically scattered by a more massive, unseen body located at smaller separations. Several ground-based observations have searched for this hypothetical Fomalhaut "c", but have yet to find it. At very small, Solar-System-like scales, any additional companions must have a mass less than thirteen times that of Jupiter. At slightly larger scales, comparable to the locations of the planets around HR 8799, any additional planets of Fomalhaut must have masses below about 2 to 7 Jupiter masses. A gaseous planet in an orbit like Fomalhaut b could have formed in situ if it coalesced from small pebble-sized objects that rapidly formed into a protoplanetary core which in turn accreted a gaseous envelope. In observations taken in May 2023 with the James Webb Space Telescope's NIRCam and NIRSpec instruments, researchers identified ten sources within the dusty rings of the Fomalhaut system. One of these, informally dubbed S7, could be a planet in orbit around Formalhaut. The upcoming Cycle 2 follow-up program aims to determine whether S7 is a background galaxy, brown dwarf, or a Jovian mass planet. Longer duration observations are anticipated to enhance signal strength and reduce noise, potentially enabling detection of smaller objects. This effort seeks to reduce the detection limit from approximately 0.6 Jupiter masses to around 0.3–0.4 Jupiter masses. Subsequent JWST observations aim to verify or dismiss the existence of S7. Furthermore, the Cycle 2 program may clarify S7's association with Fomalhaut and identify additional planets hinted at by the complex disk structure revealed in the MIRI results, as outlined by the authors. ==Gallery==

File:Fomalhaut with Disk Ring and extrasolar planet b.jpg|Fomalhaut b as observed from 2004 to 2006 (discovery image) File:NASA's Hubble Reveals Rogue Planetary Orbit For Fomalhaut B.jpg|Fomalhaut b as observed from 2004 to 2012 File:Fomalhaut planet.jpg|Artistic rendition of Fomalhaut b as a planet revolving around its parent star, a model which has now been disproven File:Fomalhaut-artist-impression-heic2006a.jpg|Visualisation of Fomalhaut and Fomalhaut b (artist's impression) == See also ==