Fork me on GitHub
an open source database of all discovered extrasolar planets

HD 20782

The planetary system HD 20782 hosts at least 3 planets. Note that the system is a multiple star system. It hosts at least 2 stellar components.

  System parameters
Primary system name HD 20782
Alternative system names HD 20781
Right ascension 03 20 03.57791
Declination -28 51 14.6651
Distance [parsec] 35.5±0.4
Distance [lightyears] 115.8±1.2
Number of stars in system 2
Number of planets in system 3

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
    •  HD 20782, stellar object
      •  HD 20782 b, planet, semi-major axis: 1.397±0.009 AU
      •  HD 20781, stellar object
        •  HD 20781 b, planet, semi-major axis: 0.169±0.003 AU
          •  HD 20781 c, planet, semi-major axis: 0.346±0.006 AU

        PlanetsPlanets in the system

        This table lists all planets in the system HD 20782.

          HD 20782 b HD 20781 b HD 20781 c
        Alternative planet names N/A N/A N/A
        Description The planet HD 20782 b is orbiting the main sequence star HD 20782, a star in a binary system in which both stars host a planetary systems. This is the first such system. The planet HD 20781 b is orbiting a star in a binary system in which both stars host a planetary systems. This is the first such system. It was announced as part of a large data release by the Euopean HARPS team. The planet HD 20781 c is orbiting a star in a binary system in which both stars host a planetary systems. This is the first such system. It was announced as part of a large data release by the Euopean HARPS team.
        Lists Confirmed planets; Planets in binary systems, S-type
        Mass [Mjup] 1.43±0.03 0.038±0.004 0.050±0.004
        Mass [Mearth] 454±10 12.0±1.1 15.8±1.2
        Radius [Rjup] N/A N/A N/A
        Radius [Rearth] N/A N/A N/A
        Orbital period [days] 597.07±0.04 29.15±0.02 85.13±0.12
        Semi-major axis [AU] 1.397±0.009 0.169±0.003 0.346±0.006
        Eccentricity 0.956±0.004 0.11±0.06 0.28±0.09
        Equilibrium temperature [K] N/A N/A N/A
        Discovery method RV
        Discovery year 2006 2011 2011
        Last updated [yy/mm/dd] 16/01/10

        starStars in the system

        This table lists all stars in the system HD 20782.

          HD 20782 HD 20781
        Alternative star names HIP 15527, TYC 6445-136-1, SAO 168469, CD-29 1231, CPD-29 382, 2MASS J03200355-2851145, WDS J03201-2851A HIP 15526, TYC 6445-983-1, SAO 168468, CD-29 1229, CPD-29 381, 2MASS J03200291-2847016, WDS J03201-2851B
        Mass [MSun] 1.02±0.02 0.760
        Radius [RSun] 1.09±0.04 N/A
        Age [Gyr] 5.5±1.4 N/A
        Metallicity [Fe/H] 0.010±0.030 -0.11±0.02
        Temperature [K] 5798±44 5256±29
        Spectral type G1.5 V G9.5V
        Visual magnitude 7.38 8.440±0.010

        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).

        PlutoMercuryMarsVenusEarthNeptuneUranusSaturnJupiterHD 20782 bHD 20781 bHD 20781 c

        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.

        HD 20782

        Habitable zoneHD 20782 b

        HD 20781

        Habitable zoneHD 20781 bHD 20781 c

        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) 2
        Hanno Rein hanno(at) 7
        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.