Imaginary Picture of K2-238 b

Display orbital revolution of K2-238 b around the hoststar K2-238
/
Exoplanet Name : K2-238 b
Alternate Name : "2MASS J23104905-0751270 b, EPIC 246067459 b, WISE J231049.06-075127.2 b"
Status : Confirmed
Radius (Rjup / Re): 1.3000 (Rjup) 14.5717 (Rearth)
Mass (Mjup / Me): 0.8600 (Mjup) 273.4267 (Mearth)
Semi Major Axis / Orbital Distance Calculated 0.0460 (AU) 0.0460 (AU Est.)
Eccentricity : 0.0000
Orbital Period(Yrs) 0.0088
Orbital Period(Observed/Estimated) 3.20 (Days Obs.) 3.30 (Days Est.)
Surface Gravity (G Earth) 1.2877
Star Radiation at Atmospheric Boundary: 1472031.1 (W/m2)
Measured Temperature (K) 0.0 (K)
Blackbody T 0.1(K) 1554.6 (K)
Blackbody T 0.3(K) 1459.9 (K)
Blackbody T 0.7(K) 1181.2 (K)
Tidally Locked Blackbody T 0.1(K) 1848.8 (K)
Tidally Locked Blackbody T 0.3(K) 1736.2 (K)
Size Class: Super-Jupiter-size
Mass Class:
Detection Type : Primary Transit
Mass Detection :
Radius Detection :
Habitability by Solar Eq. Astronomical Unit: Not habitable
Habitability by Kopparapu: Not habitable
Star Name : K2-238
Alternate Name : "2MASS J23104905-0751270, EPIC 246067459, WISE J231049.06-075127.2"
Star Distance(LY) : 1477.5
Stellar Radius(Rsun) : 1.6 (Rsun Measured)
Stellar Mass(Msun) : 1.2 (Msun Measured) 1.3 (Msun Estimated)
Star Age : 5.6 (GY)
Temperature : 5630 (K)
Spectral type : G2 V
UV portion[%]: 7.4
Visible portion[%]: 44.0
IR portion[%]: 48.6
Metalicity : 0.3
Absolute Magnitude: 5.5
Apparent Magnitude: 13.8
Right Ascension(RA) 347.7043
Declination (DEC) -7.8575
Hubble Space Telescope Guide Star Catalog (GSC) ID
Discovered by
Discovery Paper - Authors
Discovery Paper - Title
Discovery Paper - Journal
Discovery Paper - URL
SIMBAD LINK
Open Exoplanet Database Link
K2-238 b
K2-238 b

  • K2-238 b is an exoplanet orbiting the star K2-238, located about 1477.5 light-years (453.0 pc) away from Solar System. Its discovery was publicly announced on 2018.
  • The host star K2-238 has apparent magnitude of 13.8, with absolute magnitude of 5.5.
  • It is 1.2 times more massive and 1.6 times bigger compared with our Sun. The surface temperature is 5630 with its spectral types of G2 V
  • In this planetary system, the extrasolar planet K2-238 b orbits around the star K2-238 every 3.2 days with its orbital distance of 0.05 AU ( 6881502.1 km)
  • (Projected orbit of K2-238 b around its host star K2-238)


  • The Star K2-238 's habitable zone is located at the following distance
  • Inner Boundary (the orbital distance at Venus's Equivalent Radiation ) : 1.092 AU ( 163332280.7 km)
  • Earth Boundary (the orbital distance at Earth's Equivalent Radiation) : 1.509 AU ( 225767895.8 km)
  • Outer Boundary (the orbital distance at Mars's Equivalent Radiation) : 2.300 AU ( 344020310.9 km)
  • Snow Line (the orbital distance at Snow Line Equivalent Radiation) : 3.384 AU ( 506240958.0 km)
  • Radiation at Planetary Boundary of K2-238 b : 1472031.07 W/m2

    (Habitable zone calculated based on SEAU(Solar Equivalent Astronomical Unit) around the star K2-238)



  • Kopparapu Recent Venus for Star K2-238 distance : 1.142 AU
  • Kopparapu Runaway Greenhouse for Earth-sized planet for Star K2-238 distance : 1.446 AU
  • Kopparapu Runaway Greenhouse for Super-Earth-sized planet for Star K2-238 distance : 1.396 AU
  • Kopparapu Runaway Greenhouse for Mars-sized planet for Star K2-238 distance : 1.531 AU
  • Kopparapu Outer Boundary for Maximum Greenhouse for Star K2-238 distance : 2.563 AU
  • Kopparapu Outer Boundary for Early Mars for Star K2-238 distance : 2.704 AU

    (Habitable zone calculated based on Kopparapu et al.(2013) around the star K2-238)



  • Original Kopparapu Recent Venus for Star K2-238 distance : 1.140 AU
  • Original Kopparapu Runaway Greenhouse for Star K2-238 distance : 1.486 AU
  • Original Kopparapu Moist Greenhouse for Star K2-238 distance : 1.508 AU
  • Original Kopparapu Outer Boundary for Maximum Greenhouse for Star K2-238 distance : 2.608 AU
  • Original Kopparapu Outer Boundary for Early Mars for Star K2-238 distance : 2.712 AU

    (Habitable zone calculated based on Kopparapu et al.(Original) around the star K2-238)



    (Position in Stellar Map of star K2-238 and its Exoplanet K2-238 b)



    (Zoomed position in Stellar Map of star K2-238 and its Exoplanet K2-238 b (zoom level 3))

    (Synthetic Spectrum of star K2-238*)
    *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