Imaginary Picture of K2-240 c

Display orbital revolution of K2-240 c around the hoststar K2-240
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Exoplanet Name : K2-240 c
Alternate Name : "K2-240 c, 2MASS J15112391-1752307 c, EPIC 249801827 c, WISE J151123.86-175231.2 c"
Status : Confirmed
Radius (Rjup / Re): 0.1610 (Rjup) 1.8046 (Rearth)
Mass (Mjup / Me): 0.0145 (Mjup) 4.6101 (Mearth)
Semi Major Axis / Orbital Distance Calculated 0.1159 (AU) 0.1159 (AU Est.)
Eccentricity : 0.0000
Orbital Period(Yrs) 0.0562
Orbital Period(Observed/Estimated) 20.52 (Days Obs.) 18.92 (Days Est.)
Surface Gravity (G Earth) 1.4155
Star Radiation at Atmospheric Boundary: 5609.5 (W/m2)
Measured Temperature (K) 0.0 (K)
Blackbody T 0.1(K) 386.3 (K)
Blackbody T 0.3(K) 362.7 (K)
Blackbody T 0.7(K) 293.5 (K)
Tidally Locked Blackbody T 0.1(K) 459.3 (K)
Tidally Locked Blackbody T 0.3(K) 431.4 (K)
Size Class: super-Earth-size
Mass Class:
Detection Type : Primary Transit
Mass Detection : Theoretical
Radius Detection : Primary Transit
Habitability by Solar Eq. Astronomical Unit: Not habitable
Habitability by Kopparapu: Not habitable
Star Name : K2-240
Alternate Name : "K2-240, 2MASS J15112391-1752307, EPIC 249801827, WISE J151123.86-175231.2"
Star Distance(LY) : 238.2
Stellar Radius(Rsun) : 0.5 (Rsun Measured)
Stellar Mass(Msun) : 0.6 (Msun Measured) 0.5 (Msun Estimated)
Star Age : 0.0 (GY)
Temperature : 3810 (K)
Spectral type : M0.5 V
UV portion[%]: 0.4
Visible portion[%]: 16.5
IR portion[%]: 83.1
Metalicity : -0.1
Absolute Magnitude: 9.6
Apparent Magnitude: 13.9
Right Ascension(RA) 227.8496
Declination (DEC) -17.8752
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=K2-240+&submit=SIMBAD+search
Open Exoplanet Database Link
K2-240 c
K2-240 c

  • K2-240 c is an exoplanet orbiting the star K2-240, located about 238.2 light-years (73.0 pc) away from Solar System. Its discovery was publicly announced on 2018.
  • The host star K2-240 has apparent magnitude of 13.9, with absolute magnitude of 9.6.
  • It is 0.6 times more massive and 0.5 times bigger compared with our Sun. The surface temperature is 3810 with its spectral types of M0.5 V
  • In this planetary system, the extrasolar planet K2-240 c orbits around the star K2-240 every 20.5 days with its orbital distance of 0.12 AU ( 17338393.2 km)
  • (Projected orbit of K2-240 c around its host star K2-240)


  • The Star K2-240 's habitable zone is located at the following distance
  • Inner Boundary (the orbital distance at Venus's Equivalent Radiation ) : 0.170 AU ( 25403983.6 km)
  • Earth Boundary (the orbital distance at Earth's Equivalent Radiation) : 0.235 AU ( 35114944.2 km)
  • Outer Boundary (the orbital distance at Mars's Equivalent Radiation) : 0.358 AU ( 53507404.0 km)
  • Snow Line (the orbital distance at Snow Line Equivalent Radiation) : 0.526 AU ( 78738489.0 km)
  • Radiation at Planetary Boundary of K2-240 c : 5609.52 W/m2

    (Habitable zone calculated based on SEAU(Solar Equivalent Astronomical Unit) around the star K2-240)



  • Kopparapu Recent Venus for Star K2-240 distance : 0.191 AU
  • Kopparapu Runaway Greenhouse for Earth-sized planet for Star K2-240 distance : 0.242 AU
  • Kopparapu Runaway Greenhouse for Super-Earth-sized planet for Star K2-240 distance : 0.233 AU
  • Kopparapu Runaway Greenhouse for Mars-sized planet for Star K2-240 distance : 0.257 AU
  • Kopparapu Outer Boundary for Maximum Greenhouse for Star K2-240 distance : 0.463 AU
  • Kopparapu Outer Boundary for Early Mars for Star K2-240 distance : 0.489 AU

    (Habitable zone calculated based on Kopparapu et al.(2013) around the star K2-240)



  • Original Kopparapu Recent Venus for Star K2-240 distance : 0.189 AU
  • Original Kopparapu Runaway Greenhouse for Star K2-240 distance : 0.250 AU
  • Original Kopparapu Moist Greenhouse for Star K2-240 distance : 0.250 AU
  • Original Kopparapu Outer Boundary for Maximum Greenhouse for Star K2-240 distance : 0.470 AU
  • Original Kopparapu Outer Boundary for Early Mars for Star K2-240 distance : 0.489 AU

    (Habitable zone calculated based on Kopparapu et al.(Original) around the star K2-240)



    (Position in Stellar Map of star K2-240 and its Exoplanet K2-240 c)



    (Zoomed position in Stellar Map of star K2-240 and its Exoplanet K2-240 c (zoom level 3))

    (Synthetic Spectrum of star K2-240*)
    *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