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Psi-1 Draconis

The planetary system Psi-1 Draconis 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 Psi-1 Draconis
Alternative system names ψ1 Dra, ψ1 Draconis, psi01 Dra, psi01 Draconis
Right ascension 17 41 56.35536
Declination +72 08 55.8481
Distance [parsec] 22.93±0.06
Distance [lightyears] 74.79±0.20
Number of stars in system 3
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.

  •  Stellar binary
    •  Stellar binary, semi-major axis: 8.70±0.10 AU, 18.2±0.4 years
      •  Psi-1 Draconis A, stellar object
        •  Psi-1 Draconis C, stellar object
        •  Psi-1 Draconis B, stellar object
          •  Psi-1 Draconis B b, planet, semi-major axis: 4.43±0.04 AU

        PlanetsPlanets in the system

        This table lists all planets in the system Psi-1 Draconis.

          Psi-1 Draconis B b
        Alternative planet names ψ1 Dra B b, ψ1 Draconis B b, psi01 Dra B b, psi01 Draconis B b
        Description Psi-1 Draconis is a triple star system containing the spectroscopic binary Psi-1 Draconis AC, and their distant companion Psi-1 Draconis B. The radial velocities of Psi-1 Draconis B indicate the presence of a jovian planet on an eccentric, long-period orbit and a trend indicating the presence of an additional companion. The trend is not compatible with being caused by Psi-1 Draconis AC, so indicates the presence of an additional, likely substellar object outside the orbit of the known jovian planet.
        Lists Confirmed planets; Planets in binary systems, S-type
        Mass [Mjup] 1.53±0.10
        Mass [Mearth] 486±32
        Radius [Rjup] N/A
        Radius [Rearth] N/A
        Orbital period [days] 3117±42
        Semi-major axis [AU] 4.43±0.04
        Eccentricity 0.40±0.05
        Equilibrium temperature [K] N/A
        Discovery method RV
        Discovery year 2015
        Last updated [yy/mm/dd] 15/12/28

        starStars in the system

        This table lists all stars in the system Psi-1 Draconis.

          Psi-1 Draconis A Psi-1 Draconis C Psi-1 Draconis B
        Alternative star names ψ1 Dra A, ψ1 Draconis A, psi01 Dra A, psi01 Draconis A, 31 Dra A, 31 Draconis A, HD 162003 A, HIP 86614 A, TYC 4436-1425-1 A, SAO 8890 A, HR 6636 A, Gliese 694.1 A, GJ 694.1 A, GJ 9602 A, BD+72 804 A, 2MASS J17415635+7208561, WDS J17419+7209 A ψ1 Dra C, ψ1 Draconis C, psi01 Dra C, psi01 Draconis C, 31 Dra C, 31 Draconis C, HD 162003 B, HIP 86614 B, TYC 4436-1425-1 B, SAO 8890 B, HR 6636 B, Gliese 694.1 C, GJ 694.1 C, GJ 9602 C, BD+72 804 B ψ1 Dra B, ψ1 Draconis B, psi01 Dra B, psi01 Draconis B, 31 Dra B, 31 Draconis B, HD 162004, HIP 86620, TYC 4436-1424-1, SAO 8891, HR 6637, Gliese 694.1 B, GJ 694.1 B, GJ 9602 B, BD+72 805, 2MASS J17415811+7209251, WDS J17419+7209 B, STF 2241 B
        Mass [MSun] 1.430 0.526±0.005 1.19±0.07
        Radius [RSun] N/A N/A N/A
        Age [Gyr] 2.3±0.3 N/A 2.5±0.3
        Metallicity [Fe/H] -0.10±0.07 N/A 0.00±0.04
        Temperature [K] 6546±56 N/A 6213±20
        Spectral type F5IV-V K/M G0V
        Visual magnitude 4.56 N/A 5.70

        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).

        PlutoMercuryMarsVenusEarthNeptuneUranusSaturnJupiterPsi-1 Draconis B 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.

        Habitable zonePsi-1 Draconis B 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) 2
        Hanno Rein hanno(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 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.