Kepler-21

Display orbital revolution around the star Kepler-21
Imaginary Picture of Star Kepler-21
Star Name : Kepler-21
Alternate Name : "Kepler-21, 2MASS J19092683+3842505, BD+38 3455, HD 179070, HIP 94112, KIC 3632418, KOI-975, Kepler-21 A, SAO 67891, TYCą
Star Distance (LY/pc): 355.0534 (LY) 108.8600 (pc)
Stellar Radius (Rsun): 0.0000 (Rsun, measured) 1.9000 (Rsun, estimated)
Stellar Mass (Msun): 1.4100 (Msun/observed) 1.4100 (Msun/estimated)
Spectral type : F6 IV
Metalicity : -0.0300
Absolute Magnitude : 3.09
Apparent Magnitude : 8.27
Right Ascension(RA) : 287.36182
Declination(DEC) : 38.71402
  • This is the Kepler-21 . The star Kepler-21 islocated about 355.1 light-years (108.9 pc) away from our Solar System.
  • The star Kepler-21 has apparent magnitude of 8.3, with absolute magnitude of 3.1.
  • It is 1.4 times more massive and 1.9 times bigger compared with our Sun. The surface temperature is 6305 with its spectral types of F6 IV
  • Number of Extrasolar Planets : 1
  • Name of the 1 Planet Kepler-21 b radius 0.146000 mass 0.015980 orbital distance 0.042717
    (Illustration of the Kepler-21's Planetary System)



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

    Inner Boundary (the orbital distance at Venus's Equivalent Radiation ) : 1.636 AU ( 244783361.9 km)
    Earth Boundary (the orbital distance at Earth's Equivalent Radiation) : 2.262 AU ( 338354575.7 km)
    Outer Boundary (the orbital distance at Mars's Equivalent Radiation) : 3.446 AU ( 515577495.7 km)
    Snow Line (the orbital distance at Snow Line Equivalent Radiation) : 5.072 AU ( 758694870.9 km)
    (Habitable zone calculated based on SEAU(Solar Equivalent Astronomical Unit) around the star Kepler-21)



    Kopparapu's Recent Venus for Star Kepler-21 distance : 1.643 AU
    Kopparapu's Runaway Greenhouse for Earth-sized planet for Star Kepler-21 distance : 2.080 AU
    Kopparapu's Runaway Greenhouse for Super-Earth-sized planet for Star Kepler-21 distance : 2.009 AU
    Kopparapu's Runaway Greenhouse for Mars-sized planet for Star Kepler-21 distance : 2.201 AU
    Kopparapu's Outer Boundary for Maximum Greenhouse for Star Kepler-21 distance : 3.630 AU
    Kopparapu's Outer Boundary for Early Mars for Star Kepler-21 distance : 3.829 AU
    (Habitable zone calculated based on Kopparapu et al.(2013) around the star Kepler-21)



  • Original Kopparapu Recent Venus for Star Kepler-21 distance : 1.663 AU
  • Original Kopparapu Runaway Greenhouse for Star Kepler-21 distance : 2.134 AU
  • Original Kopparapu Moist Greenhouse for Star Kepler-21 distance : 2.201 AU
  • Original Kopparapu Outer Boundary for Maximum Greenhouse for Star Kepler-21 distance : 3.696 AU
  • Original Kopparapu Outer Boundary for Early Mars for Star Kepler-21 distance : 3.843 AU

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



    (Position in Stellar Map of star Kepler-21 )



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

    (Synthetic Spectrum of star HD 220773*)
    *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