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The planetary system Fomalhaut hosts at least one planet. Note that the system is a multiple star system. It hosts at least 3 stellar components.

  System parameters
Primary system name Fomalhaut
Alternative system names N/A
Right ascension 22 57 39
Declination -29 37 20
Distance [parsec] 7.70±0.03
Distance [lightyears] 25.13±0.09
Number of stars in system 3
Number of planets in system 1



This false-color composite image, taken with the Hubble Space Telescope, reveals the orbital motion of the planet Fomalhaut b. The planet will appear to cross a vast belt of debris around the star roughly 20 years from now. If the planet's orbit lies in the same plane with the belt, icy and rocky debris in the belt could crash into the planet's atmosphere and produce various phenomena. The black circle at the center of the image blocks out the light from the bright star, allowing reflected light from the belt and planet to be photographed. Credit: NASA, ESA, and P. Kalas (University of California, Berkeley and SETI Institute).

ArchitectureArchitecture of the system

This list shows all planetary and stellar components in the system. It gives a quick overview of the hierarchical architecture.

  •  Stellar binary
    •  Stellar binary
      •  Fomalhaut A, stellar object
        •  Fomalhaut b, planet, semi-major axis: 177±68 AU
        •  Fomalhaut B, stellar object
        •  Fomalhaut C, stellar object

        PlanetsPlanets in the system

        This table lists all planets in the system Fomalhaut.

          Fomalhaut b
        Alternative planet names Fomalhaut Ab, HD 216956 b, HR 8728 b, CD-30 19370 b, CPD-30 6685 b, SAO 191524 b, GJ 881 b, 2MASS J22573901-2937193 b, HIP 113368 b, IRAS 22549-2953 b, alf PsA b, 24 PsA b
        Description Formalhaut is one of the brightest stars in the night sky and located in the constellation Piscis Austrinus. It is a young star with a debris disk. In 2008 astronomers reported the discovery of a planet orbiting the star within the debris disk. Images from the Hubble space telescope show motion consistent with a Keplerian orbit that crossed the disk. However, there are still debates about where the observed emission is coming from. The object may be an isolated dust cloud or even a background neutron star.
        Lists Controversial; Planets in binary systems, S-type
        Mass [Mjup] N/A
        Mass [Mearth] N/A
        Radius [Rjup] N/A
        Radius [Rearth] N/A
        Orbital period [days] 3.20 ·105
        Semi-major axis [AU] 177±68
        Eccentricity 0.80±0.10
        Equilibrium temperature [K] N/A
        Discovery method imaging
        Discovery year 2008
        Last updated [yy/mm/dd] 13/05/12

        starStars in the system

        This table lists all stars in the system Fomalhaut.

          Fomalhaut A Fomalhaut B Fomalhaut C
        Alternative star names HD 216956, HR 8728, CD-30 19370, CPD-30 6685, SAO 191524, GJ 881, 2MASS J22573901-2937193, HIP 113368, IRAS 22549-2953, alf PsA, 24 PsA, WDS J22577-2937 A TW PsA, TW Piscis Austrini, alf PsA B, HD 216803, HIP 113283, HR 8721, TYC 7505-100-1, GJ 879, CD-32 17321, CPD-32 6550, IRAS 22536-3150, 2MASS J22562403-3133559, WDS J22577-2937 B LP 876-10, alf PsA C, 2MASS J22480446-2422075, WDS J22577-2937 C
        Mass [MSun] 1.92±0.02 0.730+0.020−0.010 0.18±0.02
        Radius [RSun] 1.840 N/A N/A
        Age [Gyr] N/A N/A N/A
        Metallicity [Fe/H] N/A N/A N/A
        Temperature [K] 8590±73 4594±80 3132±65
        Spectral type A3 V K4Ve M4V
        Visual magnitude 1.160 6.488±0.012 13.20±0.02

        Planet sizes

        The following plot shows the approximate sizes of the planets in this system The Solar System planets are shown as a comparison. Note that unless the radius has been determined through a transit observation, this is only an approximation (see Lissauer et al. 2011b).


        Habitable zone

        The following plot shows the approximate location of the planets in this system with respect to the habitable zone (green) and the size of the star (red). This is only an estimate, using the star's spectral type and mass. Note that if no green band is shown in the plot, then the planet's orbit is far outside the habitable zone. The equations of Selsis, Kasting et al are used to draw the inner and outer boundaries.

        Habitable zoneFomalhaut b

        referencesScientific references and contributors

        Links to scientific papers and other data sources


        This table lists all links which are relevant to this particular system. Note that this is just a summary. More references to the scientific publications and comments can be found in the commit messages. To see these, head over the github or click here to directly go to the git blame output of this system. In the left column of the output you can see the commit message corresponding to each parameter. It also lists the date of the last commit and the person making the changes. Within the commit message, you will find a link to the scientific publication where the data is taken from. Note that this is a new feature and not all system parameters might have a reference associated with it yet. Please help making this catalogue better and contribute data or references!

        Open Exoplanet Catalogue contributors

        Contributor E-mail Number of commits
        Andrew Tribick ajtribick(at) 3
        Hanno Rein hanno(at) 9
        Marc-Antoine Martinod marc-antoine.martinod(at) 1
        Ryan Varley ryanjvarley(at) 2

        This table lists all people who have contributed to the Open Exoplanet Catalogue. Please consider contributing! Click here to find out how. You can also view all commits contributing to this file on github.

        xmlData download

        You can download the xml file corresponding to this planetary system, which is part of the Open Exoplanet Catalogue. All information on this page has been directly generated from this XML file. You can also download the entire catalogue over at github. If you prefer to download the dataset as an ASCII tables, you might find the oec_tables repository useful.


        If you spot an error or if you can contribute additional data to this entry, please send an e-mail to Please include the corrected xml file and a reference to where the new data is coming from, ideally a scientific paper. If you are fluent with git and github, you can also create a pull request or open an issue on the Open Exoplanet Catalogue repository. Please include the reference to the relevant scientific paper in your commit message.