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an open source database of all discovered extrasolar planets

HR 8799

The planetary system HR 8799 hosts at least 4 planets.

  System parameters
Primary system name HR 8799
Alternative system names N/A
Right ascension 23 07 28.71507
Declination +21 08 03.3053
Distance [parsec] 39.4±1.1edit
Distance [lightyears] 129±4
Number of stars in system 1
Number of planets in system 4

ImageImage

 

This image shows three planets orbiting the star HR 8799. It was obtained with the Keck II telescope on Hawaii. Credit: C. Marois et al., NRC Canada.

ArchitectureArchitecture of the system

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

  •  HR 8799, stellar object
    •  HR 8799 b, planet, semi-major axis: 68.0±1.9 AU
      •  HR 8799 c, planet, semi-major axis: 42.8±1.2 AU
        •  HR 8799 d, planet, semi-major axis: 27.0±0.7 AU
          •  HR 8799 e, planet, semi-major axis: 17.0±0.5 AU

          PlanetsPlanets in the system

          This table lists all planets in the system HR 8799.

            HR 8799 b HR 8799 c HR 8799 d HR 8799 e
          Alternative planet names HD 218396 b HD 218396 c HD 218396 d HD 218396 e
          Description HR 8799 is a young Lambda Boötis star in the constellation of Pegasus. It hosts a debris disk and at least 4 planets. The outer two planets have peculiar spectral energy distributions that match a blend of L and T-type spectra.edit HR 8799 is a young Lambda Boötis star in the constellation of Pegasus. It hosts a debris disk and at least 4 planets. The outer two planets have peculiar spectral energy distributions that match a blend of L and T-type spectra.edit HR 8799 is a young Lambda Boötis star in the constellation of Pegasus. It hosts a debris disk and at least 4 planets. The inner two planets have spectral energy distributions that best match dusty L7 dwarfs.edit HR 8799 is a young Lambda Boötis star in the constellation of Pegasus. It hosts a debris disk and at least 4 planets. The inner two planets have spectral energy distributions that best match dusty L7 dwarfs.edit
          Lists Confirmed planets
          Mass [Mjup] 5.00edit 7.00edit 7.00edit 7.00edit
          Mass [Mearth] 1589 2225 2225 2225
          Radius [Rjup] 0.700edit 1.000edit 1.100edit 1.000edit
          Radius [Rearth] 7.68 10.97 12.07 10.97
          Orbital period [days] ( 1.67±0.09 )·105edit 83255±4511edit 41628±2257edit 20816±1129edit
          Semi-major axis [AU] 68.0±1.9edit 42.8±1.2edit 27.0±0.7edit 17.0±0.5edit
          Eccentricity 0.00edit 0.00edit 0.00edit 0.00edit
          Equilibrium temperature [K] 1100edit 1200edit 1200edit 1200edit
          Discovery method imaging
          Discovery year 2008 2008 2008 2010
          Last updated [yy/mm/dd] 15/11/26

          starStars in the system

          This table lists all stars in the system HR 8799.

            HR 8799
          Alternative star names V342 Peg, V342 Pegasi, HD 218396, HIP 114189, TYC 1718-2350-1, SAO 91022, BD+20 5278, 2MASS J23072869+2108033
          Mass [MSun] 1.52+0.04−0.02edit
          Radius [RSun] 1.44±0.06edit
          Age [Gyr] 0.033+0.007−0.013edit
          Metallicity [Fe/H] -0.470edit
          Temperature [K] 7193±87edit
          Spectral type kA5hF0mA5 V
          Visual magnitude 5.953±0.010edit

          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).

          PlutoMercuryMarsVenusEarthNeptuneUranusSaturnJupiterHR 8799 bHR 8799 cHR 8799 dHR 8799 e

          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 zoneHR 8799 bHR 8799 cHR 8799 dHR 8799 e

          referencesScientific references and contributors

          Links to scientific papers and other data sources

          history http://arxiv.org/abs/1511.04082
          history http://cdsads.u-strasbg.fr/abs/2012ApJ...761...57B
          history http://phl.upr.edu/projects/habitable-exoplanets-catalog/data/database
          history http://arxiv.org/abs/1511.04083

          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 2
          Hanno Rein hanno(at)hanno-rein.de 4
          Kenneth J Cott kennethjcott(at)gmail.com 1
          Marc-Antoine Martinod marc-antoine.martinod(at)ens-cachan.fr 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.

          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.