Imaginary Picture of K2-31 b

Display orbital revolution of K2-31 b around the hoststar K2-31
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Exoplanet Name : K2-31 b
Alternate Name : "EPIC 204129699 b, 2MASS J16214578-2332520 b, EPIC 204129699.01, K2-31 A b, TYC 6794-00471-1 b, WISE J162145.75-233253.2
Status : Confirmed
Radius (Rjup / Re): 1.0600 (Rjup) 11.8815 (Rearth)
Mass (Mjup / Me): 1.7740 (Mjup) 564.0220 (Mearth)
Semi Major Axis / Orbital Distance Calculated 0.0220 (AU) 0.0220 (AU Est.)
Eccentricity : 0.0000
Orbital Period(Yrs) 0.0034
Orbital Period(Observed/Estimated) 1.26 (Days Obs.) 1.25 (Days Est.)
Surface Gravity (G Earth) 3.9953
Star Radiation at Atmospheric Boundary: 1198075.9 (W/m2)
Measured Temperature (K) 0.0 (K)
Blackbody T 0.1(K) 1476.6 (K)
Blackbody T 0.3(K) 1386.7 (K)
Blackbody T 0.7(K) 1122.0 (K)
Tidally Locked Blackbody T 0.1(K) 1756.0 (K)
Tidally Locked Blackbody T 0.3(K) 1649.1 (K)
Size Class: Jupiter-size
Mass Class:
Detection Type : Primary Transit
Mass Detection : Radial Velocity
Radius Detection : Primary Transit
Habitability by Solar Eq. Astronomical Unit: Not habitable
Habitability by Kopparapu: Not habitable
Star Name : K2-31
Alternate Name : "EPIC 204129699, TYC 6794-471-1, 2MASS 16214578-2332520"
Star Distance(LY) : 342.6
Stellar Radius(Rsun) : 0.8 (Rsun Measured)
Stellar Mass(Msun) : 0.9 (Msun Measured) 0.9 (Msun Estimated)
Star Age : 0.0 (GY)
Temperature : 5280 (K)
Spectral type : G7V
UV portion[%]: 5.6
Visible portion[%]: 41.2
IR portion[%]: 53.1
Metalicity : 0.1
Absolute Magnitude: 5.7
Apparent Magnitude: 10.8
Right Ascension(RA) 245.4408
Declination (DEC) -23.5479
Hubble Space Telescope Guide Star Catalog (GSC) ID
Discovered by
Discovery Paper - Authors
Discovery Paper - Title
Discovery Paper - Journal 0
Discovery Paper - URL 0
SIMBAD LINK http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=K2-31+&submit=SIMBAD+search
Open Exoplanet Database Link
K2-31 b
K2-31 b

  • K2-31 b is an exoplanet orbiting the star K2-31 , located about 342.6 light-years (105.0 pc) away from Solar System. Its discovery was publicly announced on 2016.
  • The host star K2-31 has apparent magnitude of 10.8, with absolute magnitude of 5.7.
  • It is 0.9 times more massive and 0.8 times bigger compared with our Sun. The surface temperature is 5280 with its spectral types of G7V
  • In this planetary system, the extrasolar planet K2-31 b orbits around the star K2-31 every 1.3 days with its orbital distance of 0.02 AU ( 3291153.2 km)
  • (Projected orbit of K2-31 b around its host star K2-31 )


  • The Star K2-31 's habitable zone is located at the following distance
  • Inner Boundary (the orbital distance at Venus's Equivalent Radiation ) : 0.471 AU ( 70472643.1 km)
  • Earth Boundary (the orbital distance at Earth's Equivalent Radiation) : 0.651 AU ( 97411609.5 km)
  • Outer Boundary (the orbital distance at Mars's Equivalent Radiation) : 0.992 AU ( 148433735.7 km)
  • Snow Line (the orbital distance at Snow Line Equivalent Radiation) : 1.460 AU ( 218426744.6 km)
  • Radiation at Planetary Boundary of K2-31 b : 1198075.93 W/m2

    (Habitable zone calculated based on SEAU(Solar Equivalent Astronomical Unit) around the star K2-31 )



  • Kopparapu Recent Venus for Star K2-31 distance : 0.502 AU
  • Kopparapu Runaway Greenhouse for Earth-sized planet for Star K2-31 distance : 0.636 AU
  • Kopparapu Runaway Greenhouse for Super-Earth-sized planet for Star K2-31 distance : 0.614 AU
  • Kopparapu Runaway Greenhouse for Mars-sized planet for Star K2-31 distance : 0.674 AU
  • Kopparapu Outer Boundary for Maximum Greenhouse for Star K2-31 distance : 1.141 AU
  • Kopparapu Outer Boundary for Early Mars for Star K2-31 distance : 1.203 AU

    (Habitable zone calculated based on Kopparapu et al.(2013) around the star K2-31 )



  • Original Kopparapu Recent Venus for Star K2-31 distance : 0.499 AU
  • Original Kopparapu Runaway Greenhouse for Star K2-31 distance : 0.655 AU
  • Original Kopparapu Moist Greenhouse for Star K2-31 distance : 0.660 AU
  • Original Kopparapu Outer Boundary for Maximum Greenhouse for Star K2-31 distance : 1.160 AU
  • Original Kopparapu Outer Boundary for Early Mars for Star K2-31 distance : 1.207 AU

    (Habitable zone calculated based on Kopparapu et al.(Original) around the star K2-31 )



    (Position in Stellar Map of star K2-31 and its Exoplanet K2-31 b)



    (Zoomed position in Stellar Map of star K2-31 and its Exoplanet K2-31 b (zoom level 3))

    (Synthetic Spectrum of star K2-31 *)
    *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