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an open source database of all discovered extrasolar planets


The planetary system Kepler-20 hosts at least 5 planets.

  System parameters
Primary system name Kepler-20
Alternative system names KOI-70, KIC 6850504
Right ascension 19 10 47
Declination +42 20 19
Distance [parsec] 290edit
Distance [lightyears] 946
Number of stars in system 1
Number of planets in system 5

ArchitectureArchitecture of the system

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

  •  Kepler-20, stellar object
    •  Kepler-20 b, planet, semi-major axis: 0.0454 AU
      •  Kepler-20 c, planet, semi-major axis: 0.0930 AU
        •  Kepler-20 d, planet, semi-major axis: 0.345 AU
          •  Kepler-20 e, planet, semi-major axis: 0.0634 AU
            •  Kepler-20 f, planet, semi-major axis: 0.1378 AU

            PlanetsPlanets in the system

            This table lists all planets in the system Kepler-20.

              Kepler-20 b Kepler-20 c Kepler-20 d Kepler-20 e Kepler-20 f
            Alternative planet names 2MASS J19104752+4220194 b, KOI-70.02, KOI-70 b, KIC 6850504 b 2MASS J19104752+4220194 c, KOI-70.01, KOI-70 c, KIC 6850504 c 2MASS J19104752+4220194 d, KOI-70.03, KOI-70 d, KIC 6850504 d 2MASS J19104752+4220194 e, KOI-70.04, KOI-70 e, KIC 6850504 e 2MASS J19104752+4220194 f, KOI-70.05, KOI-70 f, KIC 6850504 f
            Description The Kepler-20 system hosts at least five transiting exo-planets. Kepler-20 b has a period of only 3.7 days. Because it is about twice as big as the Earth, it is classified as a super-Earth or sub-Neptune. Kepler-20 b's composition is ambiguous. It could be a terrestrial planet with a rocky surface or it could have a significant gas envelope.edit The Kepler-20 system hosts at least five transiting exo-planets. Kepler-20 c has a low mean density which means it cannot be composed of rocky and iron material alone but must have a gas envelope.edit The Kepler-20 system hosts at least five transiting exo-planets. Kepler-20 d has a low mean density and cannot be composed of rocky and iron material alone. The planet has an equilibrium temperature of 95C (205F).edit The Kepler-20 system hosts at least five transiting exo-planets. Kepler-20 e is most likely a rocky planet made of iron and silicates. It is approximately the size of Venus and is the first discovery of a sub-Earth size planet by the Kepler team. It is not habitable because the planet is on an orbit very close to its host star and the equilibrium temperature is as high as 1000 Kelvin (726C, 1340F).edit The Kepler-20 system hosts at least 5 transiting exo-planets. Kepler-20 f is orbiting the star every 20 days and has a size similar to that of Earth. It is too close to the star to be habitable. However, it could have developed a thick water vapour atmosphere.edit
            Lists Confirmed planets
            Mass [Mjup] 0.0270edit 0.0510edit 0.0600edit N/A N/A
            Mass [Mearth] 8.58 16.21 19.07 N/A N/A
            Radius [Rjup] 0.1700edit 0.270edit 0.250edit 0.0791edit 0.0930edit
            Radius [Rearth] 1.906 3.03 2.80 0.887 1.042
            Orbital period [days] 3.70edit 10.85edit 77.6edit 6.10edit 19.58edit
            Semi-major axis [AU] 0.0454edit 0.0930edit 0.345edit 0.0634edit 0.1378edit
            Eccentricity N/A N/A N/A N/A N/A
            Equilibrium temperature [K] 1092edit 760edit 389edit 1040edit 706edit
            Discovery method transit
            Discovery year 2011
            Last updated [yy/mm/dd] 11/12/21

            starStars in the system

            This table lists all stars in the system Kepler-20.

            Alternative star names KOI-70, KIC 6850504, 2MASS J19104752+4220194
            Mass [MSun] 0.912edit
            Radius [RSun] 0.944edit
            Age [Gyr] N/A
            Metallicity [Fe/H] 0.0200edit
            Temperature [K] 5466edit
            Spectral type G8
            Visual magnitude 12.50edit

            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).

            PlutoMercuryMarsVenusEarthNeptuneUranusSaturnJupiterKepler-20 bKepler-20 cKepler-20 dKepler-20 eKepler-20 f

            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 zoneKepler-20 bKepler-20 cKepler-20 dKepler-20 eKepler-20 f

            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) 8
            Kenneth J Cott kennethjcott(at) 1
            Marc-Antoine ma.martinod(at) 2
            Marc-Antoine Martinod marc-antoine.martinod(at) 2
            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 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.