Imaginary Picture of K2-42 b

Display orbital revolution of K2-42 b around the hoststar K2-42
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Exoplanet Name : K2-42 b
Alternate Name : "EPIC 201155177 b, EPIC 201155177.01"
Status : Confirmed
Radius (Rjup / Re): 0.1920 (Rjup) 2.1521 (Rearth)
Mass (Mjup / Me): 0.0169 (Mjup) 5.3812 (Mearth)
Semi Major Axis / Orbital Distance Calculated 0.0617 (AU) 0.0617 (AU Est.)
Eccentricity : 0.0000
Orbital Period(Yrs) 0.0183
Orbital Period(Observed/Estimated) 6.69 (Days Obs.) 6.69 (Days Est.)
Surface Gravity (G Earth) 1.1618
Star Radiation at Atmospheric Boundary: 59748.7 (W/m2)
Measured Temperature (K) 0.0 (K)
Blackbody T 0.1(K) 697.8 (K)
Blackbody T 0.3(K) 655.3 (K)
Blackbody T 0.7(K) 530.2 (K)
Tidally Locked Blackbody T 0.1(K) 829.8 (K)
Tidally Locked Blackbody T 0.3(K) 779.3 (K)
Size Class: sub-Neptune-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 : K2-42
Alternate Name : "2MASS J11463977-0510186, EPIC 201155177, WISE J114639.77-051019.1"
Star Distance(LY) : 1286.4
Stellar Radius(Rsun) : 0.6 (Rsun Measured)
Stellar Mass(Msun) : 0.7 (Msun Measured) 0.7 (Msun Estimated)
Star Age : 0.0 (GY)
Temperature : 4613 (K)
Spectral type : K4
UV portion[%]: 1.9
Visible portion[%]: 32.9
IR portion[%]: 65.2
Metalicity : 0.0
Absolute Magnitude: 5.0
Apparent Magnitude: 13.0
Right Ascension(RA) 176.6657
Declination (DEC) -5.1719
Hubble Space Telescope Guide Star Catalog (GSC) ID
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=K2-42+&submit=SIMBAD+search
Open Exoplanet Database Link
K2-42 b
K2-42 b

  • K2-42 b is an exoplanet orbiting the star K2-42, located about 1286.4 light-years (394.4 pc) away from Solar System. Its discovery was publicly announced on 2016.
  • The host star K2-42 has apparent magnitude of 13.0, with absolute magnitude of 5.0.
  • It is 0.7 times more massive and 0.6 times bigger compared with our Sun. The surface temperature is 4613 with its spectral types of K4
  • In this planetary system, the extrasolar planet K2-42 b orbits around the star K2-42 every 6.7 days with its orbital distance of 0.06 AU ( 9230188.6 km)
  • (Projected orbit of K2-42 b around its host star K2-42)


  • The Star K2-42 's habitable zone is located at the following distance
  • Inner Boundary (the orbital distance at Venus's Equivalent Radiation ) : 0.295 AU ( 44137222.1 km)
  • Earth Boundary (the orbital distance at Earth's Equivalent Radiation) : 0.408 AU ( 61009175.3 km)
  • Outer Boundary (the orbital distance at Mars's Equivalent Radiation) : 0.621 AU ( 92964481.9 km)
  • Snow Line (the orbital distance at Snow Line Equivalent Radiation) : 0.914 AU ( 136801307.6 km)
  • Radiation at Planetary Boundary of K2-42 b : 59748.67 W/m2

    (Habitable zone calculated based on SEAU(Solar Equivalent Astronomical Unit) around the star K2-42)



  • Kopparapu Recent Venus for Star K2-42 distance : 0.325 AU
  • Kopparapu Runaway Greenhouse for Earth-sized planet for Star K2-42 distance : 0.411 AU
  • Kopparapu Runaway Greenhouse for Super-Earth-sized planet for Star K2-42 distance : 0.397 AU
  • Kopparapu Runaway Greenhouse for Mars-sized planet for Star K2-42 distance : 0.436 AU
  • Kopparapu Outer Boundary for Maximum Greenhouse for Star K2-42 distance : 0.757 AU
  • Kopparapu Outer Boundary for Early Mars for Star K2-42 distance : 0.799 AU

    (Habitable zone calculated based on Kopparapu et al.(2013) around the star K2-42)



  • Original Kopparapu Recent Venus for Star K2-42 distance : 0.320 AU
  • Original Kopparapu Runaway Greenhouse for Star K2-42 distance : 0.424 AU
  • Original Kopparapu Moist Greenhouse for Star K2-42 distance : 0.424 AU
  • Original Kopparapu Outer Boundary for Maximum Greenhouse for Star K2-42 distance : 0.769 AU
  • Original Kopparapu Outer Boundary for Early Mars for Star K2-42 distance : 0.800 AU

    (Habitable zone calculated based on Kopparapu et al.(Original) around the star K2-42)



    (Position in Stellar Map of star K2-42 and its Exoplanet K2-42 b)



    (Zoomed position in Stellar Map of star K2-42 and its Exoplanet K2-42 b (zoom level 3))

    (Synthetic Spectrum of star K2-42*)
    *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