Exoplanet Name : |
GJ 238 b |
Alternate Name : |
|
Status : |
Confirmed |
Radius (Rjup / Re): |
0.0505 |
(Rjup) |
0.5661 |
(Rearth) |
Mass (Mjup / Me): |
0.0004 |
(Mjup) |
0.1330 |
(Mearth) |
Semi Major Axis / Orbital Distance Calculated |
0.0212 |
(AU) |
0.0212 |
(AU Est.) |
Eccentricity : |
0.0000 |
Orbital Period(Yrs) |
0.0048 |
Orbital Period(Observed/Estimated) |
1.74 |
(Days Obs.) |
1.74 |
(Days Est.) |
Surface Gravity (G Earth) |
0.4152 |
Star Radiation at Atmospheric Boundary: |
128572.7 |
(W/m2) |
Measured Temperature (K) |
0.0 |
(K) |
Blackbody T 0.1(K) |
845.1 |
(K) |
Blackbody T 0.3(K) |
793.7 |
(K) |
Blackbody T 0.7(K) |
642.2 |
(K) |
Tidally Locked Blackbody T 0.1(K) |
1005.0 |
(K) |
Tidally Locked Blackbody T 0.3(K) |
943.8 |
(K) |
Size Class: |
Mars-size |
Mass Class: |
|
Detection Type : |
Primary Transit |
Mass Detection : |
|
Radius Detection : |
Primary Transit |
Habitability by Solar Eq. Astronomical Unit: |
Not habitable |
Habitability by Kopparapu: |
Not habitable |
Star Name : |
GJ 238 |
Alternate Name : |
|
Star Distance(LY) : |
49.6 |
Stellar Radius(Rsun) : |
0.6 |
(Rsun Measured) |
Stellar Mass(Msun) : |
0.4 |
(Msun Measured) |
0.4 |
(Msun Estimated) |
Star Age : |
0.0 |
(GY) |
Temperature : |
3485 |
(K) |
Spectral type : |
M4 |
UV portion[%]: |
0.2 |
Visible portion[%]: |
10.4 |
IR portion[%]: |
89.4 |
Metalicity : |
0.1 |
Absolute Magnitude: |
10.7 |
Apparent Magnitude: |
11.6 |
Right Ascension(RA) |
98.4546 |
Declination (DEC) |
-58.5249 |
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 |
|
![](GJ_238_b_CSun.png) |
![](GJ_238_b_CJup.png) |
![](GJ_238_b_CNep.png) |
![](GJ_238_b_CEar.png) |
/
GJ 238 b
GJ 238 b
GJ 238 b is an exoplanet orbiting the star GJ 238, located about 49.6 light-years (15.2 pc) away from Solar System. Its discovery was publicly announced on 2024.
The host star GJ 238 has apparent magnitude of 11.6, with absolute magnitude of 10.7. It is 0.4 times more massive and 0.6 times bigger compared with our Sun. The surface temperature is 3485 with its spectral types of M4
In this planetary system, the extrasolar planet GJ 238 b orbits around the star GJ 238 every 1.7 days with its orbital distance of 0.02 AU ( 3175962.8 km)
(Projected orbit of GJ 238 b around its host star GJ 238)
![](GJ_238_b_Orb.png)
The Star GJ 238 's habitable zone is located at the following distance
Inner Boundary (the orbital distance at Venus's Equivalent Radiation )
: 0.149 AU ( 22278200.5 km)
Earth Boundary (the orbital distance at Earth's Equivalent Radiation)
: 0.206 AU ( 30794295.1 km)
Outer Boundary (the orbital distance at Mars's Equivalent Radiation)
: 0.314 AU ( 46923691.0 km)
Snow Line (the orbital distance at Snow Line Equivalent Radiation)
: 0.462 AU ( 69050266.9 km)
Radiation at Planetary Boundary of GJ 238 b : 128572.71 W/m2
(Habitable zone calculated based on SEAU(Solar Equivalent Astronomical Unit) around the star GJ 238)
![](GJ_238_b_OrbH.png)
Kopparapu Recent Venus for Star GJ 238 distance : 0.168 AU
Kopparapu Runaway Greenhouse for Earth-sized planet for Star GJ 238 distance : 0.213 AU
Kopparapu Runaway Greenhouse for Super-Earth-sized planet for Star GJ 238 distance : 0.206 AU
Kopparapu Runaway Greenhouse for Mars-sized planet for Star GJ 238 distance : 0.226 AU
Kopparapu Outer Boundary for Maximum Greenhouse for Star GJ 238 distance : 0.415 AU
Kopparapu Outer Boundary for Early Mars for Star GJ 238 distance : 0.438 AU
(Habitable zone calculated based on Kopparapu et al.(2013) around the star GJ 238)
![](GJ_238_b_OrbK.png)
Original Kopparapu Recent Venus for Star GJ 238 distance : 0.167 AU
Original Kopparapu Runaway Greenhouse for Star GJ 238 distance : 0.221 AU
Original Kopparapu Moist Greenhouse for Star GJ 238 distance : 0.221 AU
Original Kopparapu Outer Boundary for Maximum Greenhouse for Star GJ 238 distance : 0.421 AU
Original Kopparapu Outer Boundary for Early Mars for Star GJ 238 distance : 0.438 AU
(Habitable zone calculated based on Kopparapu et al.(Original) around the star GJ 238)
![](GJ_238_b_OrbKO.png)
(Position in Stellar Map of star GJ 238 and its Exoplanet GJ 238 b)
![](GJ_238_b_STZ0.png)
(Zoomed position in Stellar Map of star GJ 238 and its Exoplanet GJ 238 b (zoom level 3))
![](GJ_238_b_STZ3.png)
(Synthetic Spectrum of star GJ 238*)
![](GJ_238_b_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