Imaginary Picture of K2-390 b

Display orbital revolution of K2-390 b around the hoststar K2-390
/
Exoplanet Name : K2-390 b
Alternate Name : "TOI-4549 b, TOI-4549.01"
Status : Confirmed
Radius (Rjup / Re): 0.4163 (Rjup) 4.6657 (Rearth)
Mass (Mjup / Me): 0.0636 (Mjup) 20.2336 (Mearth)
Semi Major Axis / Orbital Distance Calculated 0.0402 (AU) 0.0402 (AU Est.)
Eccentricity : 0.0000
Orbital Period(Yrs) 0.0091
Orbital Period(Observed/Estimated) 3.31 (Days Obs.) 3.00 (Days Est.)
Surface Gravity (G Earth) 0.9295
Star Radiation at Atmospheric Boundary: 450796.9 (W/m2)
Measured Temperature (K) 0.0 (K)
Blackbody T 0.1(K) 1156.5 (K)
Blackbody T 0.3(K) 1086.1 (K)
Blackbody T 0.7(K) 878.7 (K)
Tidally Locked Blackbody T 0.1(K) 1375.3 (K)
Tidally Locked Blackbody T 0.3(K) 1291.5 (K)
Size Class: Neptune-size
Mass Class:
Detection Type : Primary Transit
Mass Detection : Theoretical
Radius Detection : Primary Transit
Habitability by Solar Eq. Astronomical Unit: Not habitable
Habitability by Kopparapu: Not habitable
Star Name : K2-390
Alternate Name : "EPIC 245995977, TOI-4549"
Star Distance(LY) : 1487.7
Stellar Radius(Rsun) : 0.8 (Rsun Measured)
Stellar Mass(Msun) : 1.0 (Msun Measured) 0.8 (Msun Estimated)
Star Age : 0.0 (GY)
Temperature : 5558 (K)
Spectral type : G5V
UV portion[%]: 7.1
Visible portion[%]: 43.6
IR portion[%]: 49.3
Metalicity : -0.1
Absolute Magnitude: 5.3
Apparent Magnitude: 13.6
Right Ascension(RA) 355.7024
Declination (DEC) -9.5887
Hubble Space Telescope Guide Star Catalog (GSC) ID
Discovered by
Discovery Paper - Authors
Discovery Paper - Title
Discovery Paper - Journal
Discovery Paper - URL
SIMBAD LINK
Open Exoplanet Database Link
K2-390 b
K2-390 b

  • K2-390 b is an exoplanet orbiting the star K2-390, located about 1487.7 light-years (456.1 pc) away from Solar System. Its discovery was publicly announced on 2022.
  • The host star K2-390 has apparent magnitude of 13.6, with absolute magnitude of 5.3.
  • It is 1.0 times more massive and 0.8 times bigger compared with our Sun. The surface temperature is 5558 with its spectral types of G5V
  • In this planetary system, the extrasolar planet K2-390 b orbits around the star K2-390 every 3.3 days with its orbital distance of 0.04 AU ( 6013834.4 km)
  • (Projected orbit of K2-390 b around its host star K2-390)


  • The Star K2-390 's habitable zone is located at the following distance
  • Inner Boundary (the orbital distance at Venus's Equivalent Radiation ) : 0.528 AU ( 78990015.8 km)
  • Earth Boundary (the orbital distance at Earth's Equivalent Radiation) : 0.730 AU ( 109184844.4 km)
  • Outer Boundary (the orbital distance at Mars's Equivalent Radiation) : 1.112 AU ( 166373540.2 km)
  • Snow Line (the orbital distance at Snow Line Equivalent Radiation) : 1.637 AU ( 244825952.8 km)
  • Radiation at Planetary Boundary of K2-390 b : 450796.86 W/m2

    (Habitable zone calculated based on SEAU(Solar Equivalent Astronomical Unit) around the star K2-390)



  • Kopparapu Recent Venus for Star K2-390 distance : 0.554 AU
  • Kopparapu Runaway Greenhouse for Earth-sized planet for Star K2-390 distance : 0.702 AU
  • Kopparapu Runaway Greenhouse for Super-Earth-sized planet for Star K2-390 distance : 0.678 AU
  • Kopparapu Runaway Greenhouse for Mars-sized planet for Star K2-390 distance : 0.744 AU
  • Kopparapu Outer Boundary for Maximum Greenhouse for Star K2-390 distance : 1.248 AU
  • Kopparapu Outer Boundary for Early Mars for Star K2-390 distance : 1.316 AU

    (Habitable zone calculated based on Kopparapu et al.(2013) around the star K2-390)



  • Original Kopparapu Recent Venus for Star K2-390 distance : 0.553 AU
  • Original Kopparapu Runaway Greenhouse for Star K2-390 distance : 0.722 AU
  • Original Kopparapu Moist Greenhouse for Star K2-390 distance : 0.732 AU
  • Original Kopparapu Outer Boundary for Maximum Greenhouse for Star K2-390 distance : 1.269 AU
  • Original Kopparapu Outer Boundary for Early Mars for Star K2-390 distance : 1.320 AU

    (Habitable zone calculated based on Kopparapu et al.(Original) around the star K2-390)



    (Position in Stellar Map of star K2-390 and its Exoplanet K2-390 b)



    (Zoomed position in Stellar Map of star K2-390 and its Exoplanet K2-390 b (zoom level 3))

    (Synthetic Spectrum of star K2-390*)
    *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