K2-21

Display orbital revolution around the star K2-21
Imaginary Picture of Star K2-21
Star Name : K2-21
Alternate Name : "2MASS 22411288-1429202, 2MASS J22411288-1429202, EPIC 206011691, WISE J224112.90-142921.1"
Star Distance (LY/pc): 273.4818 (LY) 83.8500 (pc)
Stellar Radius (Rsun): 0.0000 (Rsun, measured) 0.6500 (Rsun, estimated)
Stellar Mass (Msun): 0.6800 (Msun/observed) 0.6800 (Msun/estimated)
Spectral type : M0.0
Metalicity : -0.1100
Absolute Magnitude : 8.23
Apparent Magnitude : 12.85
Right Ascension(RA) : 340.30368
Declination(DEC) : -14.48899
  • This is the K2-21 . The star K2-21 islocated about 273.5 light-years (83.8 pc) away from our Solar System.
  • The star K2-21 has apparent magnitude of 12.8, with absolute magnitude of 8.2.
  • It is 0.7 times more massive and 0.7 times bigger compared with our Sun. The surface temperature is 4222 with its spectral types of M0.0
  • Number of Extrasolar Planets : 2
  • Name of the 1 Planet K2-21 b radius 0.164000 mass 0.014617 orbital distance 0.076000
  • Name of the 2 Planet K2-21 c radius 0.222000 mass 0.019372 orbital distance 0.107000
    (Illustration of the K2-21's Planetary System)



    The Star K2-21 's habitable zone is located at the following distance

    Inner Boundary (the orbital distance at Venus's Equivalent Radiation ) : 0.251 AU ( 37549825.8 km)
    Earth Boundary (the orbital distance at Earth's Equivalent Radiation) : 0.347 AU ( 51903672.3 km)
    Outer Boundary (the orbital distance at Mars's Equivalent Radiation) : 0.529 AU ( 79089710.3 km)
    Snow Line (the orbital distance at Snow Line Equivalent Radiation) : 0.778 AU ( 116383973.3 km)
    (Habitable zone calculated based on SEAU(Solar Equivalent Astronomical Unit) around the star K2-21)



    Kopparapu's Recent Venus for Star K2-21 distance : 0.280 AU
    Kopparapu's Runaway Greenhouse for Earth-sized planet for Star K2-21 distance : 0.354 AU
    Kopparapu's Runaway Greenhouse for Super-Earth-sized planet for Star K2-21 distance : 0.342 AU
    Kopparapu's Runaway Greenhouse for Mars-sized planet for Star K2-21 distance : 0.375 AU
    Kopparapu's Outer Boundary for Maximum Greenhouse for Star K2-21 distance : 0.664 AU
    Kopparapu's Outer Boundary for Early Mars for Star K2-21 distance : 0.701 AU
    (Habitable zone calculated based on Kopparapu et al.(2013) around the star K2-21)



  • Original Kopparapu Recent Venus for Star K2-21 distance : 0.276 AU
  • Original Kopparapu Runaway Greenhouse for Star K2-21 distance : 0.366 AU
  • Original Kopparapu Moist Greenhouse for Star K2-21 distance : 0.365 AU
  • Original Kopparapu Outer Boundary for Maximum Greenhouse for Star K2-21 distance : 0.675 AU
  • Original Kopparapu Outer Boundary for Early Mars for Star K2-21 distance : 0.702 AU

    (Habitable zone calculated based on Kopparapu et al.(Original) around the star K2-21)



    (Position in Stellar Map of star K2-21 )



    (Zoomed position in Stellar Map of star K2-21 (zoom level 3))

    (Synthetic Spectrum of star Kepler-769*)
    *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