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an open source database of all discovered extrasolar planets

gamma Cephei

The planetary system gamma Cephei hosts at least one planet. Note that the system is a multiple star system. It hosts at least 2 stellar components.

  System parameters
Primary system name gamma Cephei
Alternative system names Gamma Cephei, Errai, Alrai, GJ 903, HR 8974, HD 222404, HIP 116727
Right ascension 23 39 20.85153
Declination +77 37 56.1876
Distance [parsec] 13.52±0.03
Distance [lightyears] 44.11±0.08
Number of stars in system 2
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, semi-major axis: 20.2±0.7 AU, 74.0±0.9 years
    •  gamma Cephei A, stellar object
      •  Gamma Cephei b, planet, semi-major axis: 1.940 AU
      •  gamma Cephei B, stellar object

      PlanetsPlanets in the system

      This table lists all planets in the system gamma Cephei.

        Gamma Cephei b
      Alternative planet names Gamma Cephei A b, gam Cep A b, HD 222404 A b
      Description N/A
      Lists Confirmed planets; Planets in binary systems, S-type
      Mass [Mjup] 9.4+0.7−1.1
      Mass [Mearth] 2988+222−350
      Radius [Rjup] N/A
      Radius [Rearth] N/A
      Orbital period [days] 905
      Semi-major axis [AU] 1.940
      Eccentricity 0.0800
      Equilibrium temperature [K] N/A
      Discovery method RV
      Discovery year 2003
      Last updated [yy/mm/dd] 18/04/20

      starStars in the system

      This table lists all stars in the system gamma Cephei.

        gamma Cephei A gamma Cephei B
      Alternative star names Gamma Cephei A, gam Cep A, γ Cep A, γ Cephei A, 35 Cep A, 35 Cephei A, Errai A, Alrai A, Gliese 903 A, GJ 903 A, HR 8974 A, HD 222404 A, HIP 116727 A, TYC 4606-3584-1 A, BD+76 928 A, 2MASS J23392083+7737563 A, WDS J23393+7738 A, NHR 9 A Gamma Cephei B, gam Cep B, γ Cep B, γ Cephei B, 35 Cep B, 35 Cephei B, Errai B, Alrai B, Gliese 903 B, GJ 903 B, HR 8974 B, HD 222404 B, HIP 116727 B, TYC 4606-3584-1 B, BD+76 928 B, 2MASS J23392083+7737563 B, WDS J23393+7738 B, NHR 9 B
      Mass [MSun] 1.180 0.320
      Radius [RSun] 4.90 N/A
      Age [Gyr] N/A N/A
      Metallicity [Fe/H] 0.1800 N/A
      Temperature [K] 4800±100 N/A
      Spectral type K1 III-IV M4
      Visual magnitude 3.220±0.009 N/A

      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).

      PlutoMercuryMarsVenusEarthNeptuneUranusSaturnJupiterGamma Cephei 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 zoneGamma Cephei b

      referencesScientific references and contributors

      Links to scientific papers and other data sources

      history http://iopscience.iop.org/article/10.3847/2515-5172/aabe7e/meta
      history http://dx.doi.org/10.1051/0004-6361:20066581
      history http://dx.doi.org/10.1063/1.3556187
      history http://phl.upr.edu/projects/habitable-exoplanets-catalog/data/database
      history http://cdsads.u-strasbg.fr/abs/2007A%26A...462..777N
      history http://adsabs.harvard.edu/abs/2011AIPC.1331...88E

      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)googlemail.com 3
      Hanno Rein hanno(at)hanno-rein.de 9
      Marc-Antoine Martinod marc-antoine.martinod(at)ens-cachan.fr 1
      Tobias Mueller Tobias_Mueller(at)twam.info 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.

      correctionsCorrections

      If you spot an error or if you can contribute additional data to this entry, please send an e-mail to exoplanet@hanno-rein.de. 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.