Exoplanet Name : |
HD 81817 c |
Alternate Name : |
|
Status : |
Confirmed |
Radius (Rjup / Re): |
0.9078 |
(Rjup) |
10.1759 |
(Rearth) |
Mass (Mjup / Me): |
22.6090 |
(Mjup) |
7188.2602 |
(Mearth) |
Semi Major Axis / Orbital Distance Calculated |
2.3250 |
(AU) |
2.3250 |
(AU Est.) |
Eccentricity : |
0.0950 |
Orbital Period(Yrs) |
1.7056 |
Orbital Period(Observed/Estimated) |
623.00 |
(Days Obs.) |
624.44 |
(Days Est.) |
Surface Gravity (G Earth) |
69.4194 |
Star Radiation at Atmospheric Boundary: |
615406.5 |
(W/m2) |
Measured Temperature (K) |
0.0 |
(K) |
Blackbody T 0.1(K) |
1250.1 |
(K) |
Blackbody T 0.3(K) |
1173.9 |
(K) |
Blackbody T 0.7(K) |
949.8 |
(K) |
Tidally Locked Blackbody T 0.1(K) |
1486.6 |
(K) |
Tidally Locked Blackbody T 0.3(K) |
1396.1 |
(K) |
Size Class: |
Jupiter-size |
Mass Class: |
|
Detection Type : |
Radial Velocity |
Mass Detection : |
Radial Velocity |
Radius Detection : |
|
Habitability by Solar Eq. Astronomical Unit: |
Not habitable |
Habitability by Kopparapu: |
Not habitable |
Star Name : |
HD 81817 |
Alternate Name : |
|
Star Distance(LY) : |
877.8 |
Stellar Radius(Rsun) : |
91.4 |
(Rsun Measured) |
Stellar Mass(Msun) : |
4.3 |
(Msun Measured) |
4.3 |
(Msun Estimated) |
Star Age : |
0.1 |
(GY) |
Temperature : |
4245 |
(K) |
Spectral type : |
K3II-III |
UV portion[%]: |
0.9 |
Visible portion[%]: |
27.2 |
IR portion[%]: |
71.9 |
Metalicity : |
-0.2 |
Absolute Magnitude: |
-2.7 |
Apparent Magnitude: |
4.4 |
Right Ascension(RA) |
144.2708 |
Declination (DEC) |
81.3097 |
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 |
|
![](HD_81817_c_CSun.png) |
![](HD_81817_c_CJup.png) |
![](HD_81817_c_CNep.png) |
![](HD_81817_c_CEar.png) |
/
HD 81817 c
HD 81817 c
HD 81817 c is an exoplanet orbiting the star HD 81817, located about 877.8 light-years (269.1 pc) away from Solar System. Its discovery was publicly announced on 2022.
The host star HD 81817 has apparent magnitude of 4.4, with absolute magnitude of -2.7. It is 4.3 times more massive and 91.4 times bigger compared with our Sun. The surface temperature is 4245 with its spectral types of K3II-III
In this planetary system, the extrasolar planet HD 81817 c orbits around the star HD 81817 every 623.0 days with its orbital distance of 2.33 AU ( 347815049.4 km)
(Projected orbit of HD 81817 c around its host star HD 81817)
![](HD_81817_c_Orb.png)
The Star HD 81817 's habitable zone is located at the following distance
Inner Boundary (the orbital distance at Venus's Equivalent Radiation )
: 35.681 AU ( 5337768044.4 km)
Earth Boundary (the orbital distance at Earth's Equivalent Radiation)
: 49.320 AU ( 7378190362.9 km)
Outer Boundary (the orbital distance at Mars's Equivalent Radiation)
: 75.153 AU ( 11242729323.0 km)
Snow Line (the orbital distance at Snow Line Equivalent Radiation)
: 110.591 AU ( 16544168711.1 km)
Radiation at Planetary Boundary of HD 81817 c : 615406.48 W/m2
(Habitable zone calculated based on SEAU(Solar Equivalent Astronomical Unit) around the star HD 81817)
![](HD_81817_c_OrbH.png)
Kopparapu Recent Venus for Star HD 81817 distance : 39.728 AU
Kopparapu Runaway Greenhouse for Earth-sized planet for Star HD 81817 distance : 50.288 AU
Kopparapu Runaway Greenhouse for Super-Earth-sized planet for Star HD 81817 distance : 48.571 AU
Kopparapu Runaway Greenhouse for Mars-sized planet for Star HD 81817 distance : 53.366 AU
Kopparapu Outer Boundary for Maximum Greenhouse for Star HD 81817 distance : 94.287 AU
Kopparapu Outer Boundary for Early Mars for Star HD 81817 distance : 99.465 AU
(Habitable zone calculated based on Kopparapu et al.(2013) around the star HD 81817)
![](HD_81817_c_OrbK.png)
Original Kopparapu Recent Venus for Star HD 81817 distance : 39.205 AU
Original Kopparapu Runaway Greenhouse for Star HD 81817 distance : 51.961 AU
Original Kopparapu Moist Greenhouse for Star HD 81817 distance : 51.875 AU
Original Kopparapu Outer Boundary for Maximum Greenhouse for Star HD 81817 distance : 95.808 AU
Original Kopparapu Outer Boundary for Early Mars for Star HD 81817 distance : 99.637 AU
(Habitable zone calculated based on Kopparapu et al.(Original) around the star HD 81817)
![](HD_81817_c_OrbKO.png)
(Position in Stellar Map of star HD 81817 and its Exoplanet HD 81817 c)
![](HD_81817_c_STZ0.png)
(Zoomed position in Stellar Map of star HD 81817 and its Exoplanet HD 81817 c (zoom level 3))
![](HD_81817_c_STZ3.png)
(Synthetic Spectrum of star HD 81817*)
![](HD_81817_c_Spc.png)
*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