Imaginary Picture of K2-321 b

Display orbital revolution of K2-321 b around the hoststar K2-321
/
Exoplanet Name : K2-321 b
Alternate Name : "2MASS J10253725+0230516 b, EPIC 248480671 b, TIC 277833995 b, WISE J102537.29+023050.5 b"
Status : Confirmed
Radius (Rjup / Re): 0.1740 (Rjup) 1.9504 (Rearth)
Mass (Mjup / Me): 0.0154 (Mjup) 4.9104 (Mearth)
Semi Major Axis / Orbital Distance Calculated 0.0410 (AU) 0.0410 (AU Est.)
Eccentricity : 0.0000
Orbital Period(Yrs) 0.0063
Orbital Period(Observed/Estimated) 2.30 (Days Obs.) 3.91 (Days Est.)
Surface Gravity (G Earth) 1.2909
Star Radiation at Atmospheric Boundary: 54198.9 (W/m2)
Measured Temperature (K) 0.0 (K)
Blackbody T 0.1(K) 681.0 (K)
Blackbody T 0.3(K) 639.5 (K)
Blackbody T 0.7(K) 517.4 (K)
Tidally Locked Blackbody T 0.1(K) 809.8 (K)
Tidally Locked Blackbody T 0.3(K) 760.5 (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 : K2-321
Alternate Name : "2MASS J10253725+0230516, EPIC 248480671, TIC 277833995, WISE J102537.29+023050.5"
Star Distance(LY) : 254.0
Stellar Radius(Rsun) : 0.6 (Rsun Measured)
Stellar Mass(Msun) : 0.6 (Msun Measured) 1.7 (Msun Estimated)
Star Age : 0.0 (GY)
Temperature : 3855 (K)
Spectral type : M0
UV portion[%]: 0.5
Visible portion[%]: 20.7
IR portion[%]: 78.8
Metalicity : 0.0
Absolute Magnitude: 6.0
Apparent Magnitude: 10.5
Right Ascension(RA) 156.4053
Declination (DEC) 2.5143
Hubble Space Telescope Guide Star Catalog (GSC) ID
Discovered by
Discovery Paper - Authors
Discovery Paper - Title
Discovery Paper - Journal
Discovery Paper - URL
SIMBAD LINK https://simbad.u-strasbg.fr/simbad/sim-basic?Ident=K2-321&submit=SIMBAD+search
Open Exoplanet Database Link
K2-321 b
K2-321 b

  • K2-321 b is an exoplanet orbiting the star K2-321, located about 254.0 light-years (77.9 pc) away from Solar System. Its discovery was publicly announced on 2020.
  • The host star K2-321 has apparent magnitude of 10.5, with absolute magnitude of 6.0.
  • It is 0.6 times more massive and 0.6 times bigger compared with our Sun. The surface temperature is 3855 with its spectral types of M0
  • In this planetary system, the extrasolar planet K2-321 b orbits around the star K2-321 every 2.3 days with its orbital distance of 0.04 AU ( 6133512.7 km)
  • (Projected orbit of K2-321 b around its host star K2-321)


  • The Star K2-321 's habitable zone is located at the following distance
  • Inner Boundary (the orbital distance at Venus's Equivalent Radiation ) : 0.187 AU ( 27934112.0 km)
  • Earth Boundary (the orbital distance at Earth's Equivalent Radiation) : 0.258 AU ( 38612242.9 km)
  • Outer Boundary (the orbital distance at Mars's Equivalent Radiation) : 0.393 AU ( 58836513.3 km)
  • Snow Line (the orbital distance at Snow Line Equivalent Radiation) : 0.579 AU ( 86580506.8 km)
  • Radiation at Planetary Boundary of K2-321 b : 54198.92 W/m2

    (Habitable zone calculated based on SEAU(Solar Equivalent Astronomical Unit) around the star K2-321)



  • Kopparapu Recent Venus for Star K2-321 distance : 0.210 AU
  • Kopparapu Runaway Greenhouse for Earth-sized planet for Star K2-321 distance : 0.266 AU
  • Kopparapu Runaway Greenhouse for Super-Earth-sized planet for Star K2-321 distance : 0.256 AU
  • Kopparapu Runaway Greenhouse for Mars-sized planet for Star K2-321 distance : 0.282 AU
  • Kopparapu Outer Boundary for Maximum Greenhouse for Star K2-321 distance : 0.508 AU
  • Kopparapu Outer Boundary for Early Mars for Star K2-321 distance : 0.536 AU

    (Habitable zone calculated based on Kopparapu et al.(2013) around the star K2-321)



  • Original Kopparapu Recent Venus for Star K2-321 distance : 0.207 AU
  • Original Kopparapu Runaway Greenhouse for Star K2-321 distance : 0.275 AU
  • Original Kopparapu Moist Greenhouse for Star K2-321 distance : 0.274 AU
  • Original Kopparapu Outer Boundary for Maximum Greenhouse for Star K2-321 distance : 0.516 AU
  • Original Kopparapu Outer Boundary for Early Mars for Star K2-321 distance : 0.536 AU

    (Habitable zone calculated based on Kopparapu et al.(Original) around the star K2-321)



    (Position in Stellar Map of star K2-321 and its Exoplanet K2-321 b)



    (Zoomed position in Stellar Map of star K2-321 and its Exoplanet K2-321 b (zoom level 3))

    (Synthetic Spectrum of star K2-321*)
    *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