Imaginary Picture of HD 217850 b

Display orbital revolution of HD 217850 b around the hoststar HD 217850
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Exoplanet Name : HD 217850 b
Alternate Name :
Status : Confirmed
Radius (Rjup / Re): 0.9078 (Rjup) 10.1759 (Rearth)
Mass (Mjup / Me): 22.1600 (Mjup) 7045.5061 (Mearth)
Semi Major Axis / Orbital Distance Calculated 4.6560 (AU) 4.6560 (AU Est.)
Eccentricity : 0.7584
Orbital Period(Yrs) 9.6044
Orbital Period(Observed/Estimated) 3508.10 (Days Obs.) 3615.69 (Days Est.)
Surface Gravity (G Earth) 68.0408
Star Radiation at Atmospheric Boundary: 51.6 (W/m2)
Measured Temperature (K) 0.0 (K)
Blackbody T 0.1(K) 119.6 (K)
Blackbody T 0.3(K) 112.3 (K)
Blackbody T 0.7(K) 90.9 (K)
Tidally Locked Blackbody T 0.1(K) 142.2 (K)
Tidally Locked Blackbody T 0.3(K) 133.6 (K)
Size Class: Jupiter-size
Mass Class:
Detection Type : Radial Velocity
Mass Detection : Radial Velocity
Radius Detection :
Habitability by Solar Eq. Astronomical Unit: Not habitable
Habitability by Kopparapu: Not habitable
Star Name : HD 217850
Alternate Name :
Star Distance(LY) : 214.9
Stellar Radius(Rsun) : 1.0 (Rsun Estimated)
Stellar Mass(Msun) : 1.0 (Msun Measured) 1.1 (Msun Estimated)
Star Age : 7.6 (GY)
Temperature : 5440 (K)
Spectral type : G8V
UV portion[%]: 6.6
Visible portion[%]: 42.8
IR portion[%]: 50.6
Metalicity : 0.3
Absolute Magnitude: 4.4
Apparent Magnitude: 8.5
Right Ascension(RA) 345.6528
Declination (DEC) 58.8761
Hubble Space Telescope Guide Star Catalog (GSC) ID 03997-01744
Discovered by
Discovery Paper - Authors
Discovery Paper - Title
Discovery Paper - Journal
Discovery Paper - URL
SIMBAD LINK http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+217850&submit=SIMBAD+search
Open Exoplanet Database Link
HD 217850 b
HD 217850 b

  • HD 217850 b is an exoplanet orbiting the star HD 217850, located about 214.9 light-years (65.9 pc) away from Solar System. Its discovery was publicly announced on 2018.
  • The host star HD 217850 has apparent magnitude of 8.5, with absolute magnitude of 4.4.
  • It is 1.0 times more massive and 1.0 times bigger compared with our Sun. The surface temperature is 5440 with its spectral types of G8V
  • In this planetary system, the extrasolar planet HD 217850 b orbits around the star HD 217850 every 3508.1 days with its orbital distance of 4.66 AU ( 696527686.0 km)
  • (Projected orbit of HD 217850 b around its host star HD 217850)


  • The Star HD 217850 's habitable zone is located at the following distance
  • Inner Boundary (the orbital distance at Venus's Equivalent Radiation ) : 0.654 AU ( 97851930.0 km)
  • Earth Boundary (the orbital distance at Earth's Equivalent Radiation) : 0.904 AU ( 135256939.1 km)
  • Outer Boundary (the orbital distance at Mars's Equivalent Radiation) : 1.378 AU ( 206101642.8 km)
  • Snow Line (the orbital distance at Snow Line Equivalent Radiation) : 2.027 AU ( 303287596.2 km)
  • Radiation at Planetary Boundary of HD 217850 b : 51.57 W/m2

    (Habitable zone calculated based on SEAU(Solar Equivalent Astronomical Unit) around the star HD 217850)



  • Kopparapu Recent Venus for Star HD 217850 distance : 0.691 AU
  • Kopparapu Runaway Greenhouse for Earth-sized planet for Star HD 217850 distance : 0.876 AU
  • Kopparapu Runaway Greenhouse for Super-Earth-sized planet for Star HD 217850 distance : 0.846 AU
  • Kopparapu Runaway Greenhouse for Mars-sized planet for Star HD 217850 distance : 0.928 AU
  • Kopparapu Outer Boundary for Maximum Greenhouse for Star HD 217850 distance : 1.562 AU
  • Kopparapu Outer Boundary for Early Mars for Star HD 217850 distance : 1.647 AU

    (Habitable zone calculated based on Kopparapu et al.(2013) around the star HD 217850)



  • Original Kopparapu Recent Venus for Star HD 217850 distance : 0.688 AU
  • Original Kopparapu Runaway Greenhouse for Star HD 217850 distance : 0.901 AU
  • Original Kopparapu Moist Greenhouse for Star HD 217850 distance : 0.911 AU
  • Original Kopparapu Outer Boundary for Maximum Greenhouse for Star HD 217850 distance : 1.589 AU
  • Original Kopparapu Outer Boundary for Early Mars for Star HD 217850 distance : 1.652 AU

    (Habitable zone calculated based on Kopparapu et al.(Original) around the star HD 217850)



    (Position in Stellar Map of star HD 217850 and its Exoplanet HD 217850 b)



    (Zoomed position in Stellar Map of star HD 217850 and its Exoplanet HD 217850 b (zoom level 3))

    (Synthetic Spectrum of star HD 217850*)
    *Yamashiki YA et al. 2019 ApJ 881 114
    MUSCLES Paper I - France et al. 2016 ApJ 820 89
    MUSCLES Paper II- Youngblood et al. 2016 ApJ 824 101
    MUSCLES Paper III- Loyd et al. 2016 ApJ 824 102