HAT-P-21

Display orbital revolution around the star HAT-P-21
Imaginary Picture of Star HAT-P-21
Star Name : HAT-P-21
Alternate Name :
Star Distance (LY/pc): 874.4129 (LY) 268.0965 (pc)
Stellar Radius (Rsun): 0.0000 (Rsun, measured) 1.1050 (Rsun, estimated)
Stellar Mass (Msun): 0.9470 (Msun/observed) 0.9470 (Msun/estimated)
Spectral type : G3
Metalicity : 0.0100
Absolute Magnitude : 4.32
Apparent Magnitude : 11.46
Right Ascension(RA) : 171.27494
Declination(DEC) : 41.02806
  • This is the HAT-P-21 . The star HAT-P-21 islocated about 874.4 light-years (268.1 pc) away from our Solar System.
  • The star HAT-P-21 has apparent magnitude of 11.5, with absolute magnitude of 4.3.
  • It is 0.9 times more massive and 1.1 times bigger compared with our Sun. The surface temperature is 5588 with its spectral types of G3
  • Number of Extrasolar Planets : 1
  • Name of the 1 Planet HAT-P-21 b radius 1.024000 mass 4.063000 orbital distance 0.049400
    (Illustration of the HAT-P-21's Planetary System)



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

    Inner Boundary (the orbital distance at Venus's Equivalent Radiation ) : 0.747 AU ( 111823526.8 km)
    Earth Boundary (the orbital distance at Earth's Equivalent Radiation) : 1.033 AU ( 154569337.0 km)
    Outer Boundary (the orbital distance at Mars's Equivalent Radiation) : 1.574 AU ( 235529463.5 km)
    Snow Line (the orbital distance at Snow Line Equivalent Radiation) : 2.317 AU ( 346591923.4 km)
    (Habitable zone calculated based on SEAU(Solar Equivalent Astronomical Unit) around the star HAT-P-21)



    Kopparapu's Recent Venus for Star HAT-P-21 distance : 0.784 AU
    Kopparapu's Runaway Greenhouse for Earth-sized planet for Star HAT-P-21 distance : 0.992 AU
    Kopparapu's Runaway Greenhouse for Super-Earth-sized planet for Star HAT-P-21 distance : 0.958 AU
    Kopparapu's Runaway Greenhouse for Mars-sized planet for Star HAT-P-21 distance : 1.051 AU
    Kopparapu's Outer Boundary for Maximum Greenhouse for Star HAT-P-21 distance : 1.762 AU
    Kopparapu's Outer Boundary for Early Mars for Star HAT-P-21 distance : 1.858 AU
    (Habitable zone calculated based on Kopparapu et al.(2013) around the star HAT-P-21)



  • Original Kopparapu Recent Venus for Star HAT-P-21 distance : 0.782 AU
  • Original Kopparapu Runaway Greenhouse for Star HAT-P-21 distance : 1.020 AU
  • Original Kopparapu Moist Greenhouse for Star HAT-P-21 distance : 1.034 AU
  • Original Kopparapu Outer Boundary for Maximum Greenhouse for Star HAT-P-21 distance : 1.792 AU
  • Original Kopparapu Outer Boundary for Early Mars for Star HAT-P-21 distance : 1.864 AU

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



    (Position in Stellar Map of star HAT-P-21 )



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

    (Synthetic Spectrum of star GJ 876*)
    *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