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an open source database of all discovered extrasolar planets

81 Cet

The planetary system 81 Cet hosts at least one planet.

  System parameters
Primary system name 81 Cet
Alternative system names N/A
Right ascension 02 37 42.80105
Declination -03 23 46.2201
Distance [parsec] 92±4edit
Distance [lightyears] 302±13
Number of stars in system 1
Number of planets in system 1

ArchitectureArchitecture of the system

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

  •  81 Cet, stellar object
    •  81 Cet b, planet, semi-major axis: 2.50 AU

    PlanetsPlanets in the system

    This table lists all planets in the system 81 Cet.

      81 Cet b
    Alternative planet names 81 Ceti b, HD 16400 b
    Description The star 81 Ceti is a G-type giant in the constellation of Cetus.edit
    Lists Confirmed planets
    Mass [Mjup] 5.30edit
    Mass [Mearth] 1684
    Radius [Rjup] N/A
    Radius [Rearth] N/A
    Orbital period [days] 953±9edit
    Semi-major axis [AU] 2.50edit
    Eccentricity 0.21±0.03edit
    Equilibrium temperature [K] N/A
    Discovery method RV
    Discovery year 2008
    Last updated [yy/mm/dd] 15/09/20

    starStars in the system

    This table lists all stars in the system 81 Cet.

      81 Cet
    Alternative star names 81 Ceti, HD 16400, HIP 12247, TYC 4701-1094-1, SAO 130026, HR 771, BD-04 436, 2MASS J02374179-0323462
    Mass [MSun] 2.40edit
    Radius [RSun] 11.00edit
    Age [Gyr] N/A
    Metallicity [Fe/H] -0.0600edit
    Temperature [K] 4790edit
    Spectral type G5III
    Visual magnitude 5.65edit

    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).

    PlutoMercuryMarsVenusEarthNeptuneUranusSaturnJupiter81 Cet b

    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.

    81 Cet 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) 1
    Hanno Rein hanno(at) 4
    Marc-Antoine Martinod marc-antoine.martinod(at) 1

    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 usefule.


    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.