Fomalhaut C
Location of Fomalhaut C in the constellation Aquarius | |
Observation data J2000
| |
---|---|
Constellation | Aquarius |
Right ascension | 22h 48m 04.49285s[1] |
Declination | −24° 22′ 07.7178″[1] |
Apparent magnitude (V) | 12.624[2] |
Characteristics | |
Spectral type | M4V[3] |
Absolute magnitude (MV) | 13.21 ± 0.02[3] |
Details dex | |
Rotation | 0.466 days |
J22480446-2422075, Gaia DR2 6623351805412369024 | |
Database references | |
SIMBAD | data |
Fomalhaut C, also designated LP 876-10, is the distant third
Discovery and observation
Fomalhaut C was catalogued as a
Debris disk
Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
Debris disk | 26.4±0.6 AU | 44±3° | — |
In December 2013, a
The disk was directly detected by ALMA in 2021[7] and by JWST in 2024.[11]
Comets
In addition to the debris disk, there are also comets orbiting Fomalhaut C.[12] The debris disk orbiting C is sometimes referred to as a comet belt, due to some very elliptical orbits. The disk around Fomalhaut A is also thought to have many comets, as it is also elliptical. The Fomalhaut A belt is thought to possibly be due to a close encounter with either an undiscovered exoplanet, Fomalhaut B, or Fomalhaut C. With both A and C having comet belts, the absence of one around B is a mystery. Not only does the presence of comets make the belt more elliptical, it also makes it brighter which takes a part in its discovery.[13][14]
It has been hypothesized that Fomalhaut C could have hidden exoplanets within its belt of comets and asteroids.[15] It has also been hypothesized that A & C have interacted which could have formed C's comet belt if the interaction involved A giving up comets and debris.[16] With Fomalhaut B not having any discs or belts around it, it could have been unaffected by the encounter between them.
Orbit
The orbit of Fomalhaut C around A is estimated to take 20 million years to complete.[17] Due to the age of the three stars being 440 million years, and the distance of 2.5 light-years, this would mean that Fomalhaut C has only completed a full orbit around Fomalhaut A 22 times.[18] The tidal radius of the Fomalhaut system is 6.2 light-years (1.9 parsecs), which makes Fomalhaut C well within it, which further proves the Fomalhaut system as trinary.
See also
- Fomalhaut
- TW Piscis Austrini (Fomalhaut B)
- Fomalhaut b
Notes
- ^ Radius calculated with temperature and luminosity
References
- ^ S2CID 244398875. Gaia DR3 record for this source at VizieR.
- Bibcode:2012yCat.1322....0Z.
- ^ S2CID 67821813.
- ^ a b King, Bob (2014-10-01). "Fomalhaut: A Crazy-Wide Triple Star". Sky & Telescope. Retrieved 2016-01-17.
When you next look at Fomalhaut twinkling above the fall leaves, put four fingers together and hold them up against the sky. They'll cover about 8°, or the amount of real estate spanned by the triple system.
- ^ "Researchers find that bright nearby double star Fomalhaut is actually a triple". Astronomy.com. 2013-10-08. Retrieved 2016-01-17.
- ^ "Fomalhaut: Actually Triple Star, Astronomers Say | Astronomy". Sci-News.com. 2013-10-04. Retrieved 2016-01-17.
- ^ .
- S2CID 53600511.
- ^ "Fomalhaut's Little Sibling Has a Debris Disk Too". Astrobites.org. 2013-12-31. Retrieved 2016-01-17.
- ^ Hall, Shannon (2014-01-21). "Surprise! Fomalhaut's Kid Sister Has a Debris Disk Too". Universe Today. Retrieved 2016-01-17.
- arXiv:2405.00573 [astro-ph.EP].
- ^ "Companion's comets the key to curious exoplanet system?". Ras.org.uk. Retrieved 2016-01-17.
- ^ "Herschel Discovers a Comet Belt around Fomalhaut C". SciTech Daily. 2013-12-18. Retrieved 2016-01-15.
- ^ "Second Asteroid Ring Found In Three-Star Planetary System". Headlines & Global News. 2013-12-28. Retrieved 2016-01-15.
- ^ "Fomalhaut's Stellar Sister's Comets: Exoplanet Goldmine? : Discovery News". News.discovery.com. 2013-12-18. Archived from the original on 2016-03-11. Retrieved 2016-01-17.
- ^ Paul Gilster. "Cometary Clues to the Fomalhaut System?". Centauri-dreams.org. Retrieved 2016-01-17.
- ^ "ScienceShot: A 20-Million-Year Orbit". Science | AAAS. Aaas.org. 2013-10-03. Retrieved 2016-01-15.
- ^ "The existence of a third star in the Fomalhaut system - Spacefan.org". Spacefan.org. Archived from the original on 2014-05-15. Retrieved 2016-01-15.