Imaginary Picture of K2-181 b

Display orbital revolution of K2-181 b around the hoststar K2-181
/
Exoplanet Name : K2-181 b
Alternate Name : "2MASS J08301297+1054371 b, EPIC 211355342 b, EPIC 211355342.01, WISE J083012.98+105436.7 b"
Status : Confirmed
Radius (Rjup / Re): 0.2530 (Rjup) 2.8359 (Rearth)
Mass (Mjup / Me): 0.0219 (Mjup) 6.9552 (Mearth)
Semi Major Axis / Orbital Distance Calculated 0.0706 (AU) 0.0706 (AU Est.)
Eccentricity : 0.0000
Orbital Period(Yrs) 0.0189
Orbital Period(Observed/Estimated) 6.89 (Days Obs.) 6.89 (Days Est.)
Surface Gravity (G Earth) 0.8648
Star Radiation at Atmospheric Boundary: 278608.9 (W/m2)
Measured Temperature (K) 0.0 (K)
Blackbody T 0.1(K) 1025.4 (K)
Blackbody T 0.3(K) 963.0 (K)
Blackbody T 0.7(K) 779.1 (K)
Tidally Locked Blackbody T 0.1(K) 1219.4 (K)
Tidally Locked Blackbody T 0.3(K) 1145.2 (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 : K2-181
Alternate Name : "2MASS J08301297+1054371, EPIC 211355342, WISE J083012.98+105436.7"
Star Distance(LY) : 1173.7
Stellar Radius(Rsun) : 1.1 (Rsun Measured)
Stellar Mass(Msun) : 1.0 (Msun Measured) 1.0 (Msun Estimated)
Star Age : 0.0 (GY)
Temperature : 5608 (K)
Spectral type : G6
UV portion[%]: 7.3
Visible portion[%]: 43.9
IR portion[%]: 48.8
Metalicity : 0.2
Absolute Magnitude: 3.7
Apparent Magnitude: 11.4
Right Ascension(RA) 127.5540
Declination (DEC) 10.9103
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=K2-181+&submit=SIMBAD+search
Open Exoplanet Database Link
K2-181 b
K2-181 b

  • K2-181 b is an exoplanet orbiting the star K2-181, located about 1173.7 light-years (359.9 pc) away from Solar System. Its discovery was publicly announced on 2018.
  • The host star K2-181 has apparent magnitude of 11.4, with absolute magnitude of 3.7.
  • It is 1.0 times more massive and 1.1 times bigger compared with our Sun. The surface temperature is 5608 with its spectral types of G6
  • In this planetary system, the extrasolar planet K2-181 b orbits around the star K2-181 every 6.9 days with its orbital distance of 0.07 AU ( 10561609.7 km)
  • (Projected orbit of K2-181 b around its host star K2-181)


  • The Star K2-181 's habitable zone is located at the following distance
  • Inner Boundary (the orbital distance at Venus's Equivalent Radiation ) : 0.729 AU ( 109058093.2 km)
  • Earth Boundary (the orbital distance at Earth's Equivalent Radiation) : 1.008 AU ( 150746785.1 km)
  • Outer Boundary (the orbital distance at Mars's Equivalent Radiation) : 1.535 AU ( 229704740.3 km)
  • Snow Line (the orbital distance at Snow Line Equivalent Radiation) : 2.260 AU ( 338020588.0 km)
  • Radiation at Planetary Boundary of K2-181 b : 278608.90 W/m2

    (Habitable zone calculated based on SEAU(Solar Equivalent Astronomical Unit) around the star K2-181)



  • Kopparapu Recent Venus for Star K2-181 distance : 0.763 AU
  • Kopparapu Runaway Greenhouse for Earth-sized planet for Star K2-181 distance : 0.967 AU
  • Kopparapu Runaway Greenhouse for Super-Earth-sized planet for Star K2-181 distance : 0.933 AU
  • Kopparapu Runaway Greenhouse for Mars-sized planet for Star K2-181 distance : 1.024 AU
  • Kopparapu Outer Boundary for Maximum Greenhouse for Star K2-181 distance : 1.715 AU
  • Kopparapu Outer Boundary for Early Mars for Star K2-181 distance : 1.809 AU

    (Habitable zone calculated based on Kopparapu et al.(2013) around the star K2-181)



  • Original Kopparapu Recent Venus for Star K2-181 distance : 0.762 AU
  • Original Kopparapu Runaway Greenhouse for Star K2-181 distance : 0.994 AU
  • Original Kopparapu Moist Greenhouse for Star K2-181 distance : 1.008 AU
  • Original Kopparapu Outer Boundary for Maximum Greenhouse for Star K2-181 distance : 1.745 AU
  • Original Kopparapu Outer Boundary for Early Mars for Star K2-181 distance : 1.815 AU

    (Habitable zone calculated based on Kopparapu et al.(Original) around the star K2-181)



    (Position in Stellar Map of star K2-181 and its Exoplanet K2-181 b)



    (Zoomed position in Stellar Map of star K2-181 and its Exoplanet K2-181 b (zoom level 3))

    (Synthetic Spectrum of star K2-181*)
    *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