HD 209458 b
An artistic scene associated with HD 209458 b. The scientific record below anchors the setting; it does not establish the depicted environment.
The imagined scene
The host system is real. All alien organisms, robots, societies and social histories are fictional. Moons, rings, terrain and weather are artistic assumptions unless specifically supported by a cited source. These images are not calibrated simulations of the sky.
The scientific anchor
This illustration is associated with HD 209458 b, a catalogued exoplanet orbiting HD 209458. The available catalog measurements below describe the real system; they do not establish the illustrated scenery.
Henry et al. 2000 · Stassun et al. 2017 · Southworth 2010 · Bonomo et al. 2017 · ExoFOP
Available measurements
Host: HD 209458 · 1 catalog star(s) · Giant-size planet
NASA composite catalog values may combine different papers. Errors and upper/lower limits are retained. “Calculated Value” means derived or estimated. Msini is a minimum mass. Missing values are unknown. A multiple-star system’s single stellar row does not describe every component. Equilibrium temperature is not a measured surface temperature.
| Quantity | Value & uncertainty | Unit | Paper / source |
|---|---|---|---|
| Planet radius | 15.581 [+0.22418 / -0.22418] | Earth radii | Stassun et al. 2017 |
| Planet mass | 232.02 [+12.713 / -12.713] | Earth masses | Stassun et al. 2017 |
| Bulk density | 0.362 [+0.006 / -0.006] | g/cm³ | Southworth 2010 |
| Orbital period | 3.5247 [+3.8e-07 / -3.8e-07] | days | Stassun et al. 2017 |
| Orbital semimajor axis | 0.04707 [+0.00045 / -0.00047] | AU | Bonomo et al. 2017 |
| Orbital eccentricity | 0 | Stassun et al. 2017 | |
| Orbital inclination | 86.71 [+0.05 / -0.05] | degrees | Stassun et al. 2017 |
| Irradiation | 587.1 | Earth flux | ExoFOP |
| Equilibrium temperature | 1,459 [+12 / -12] | K; not surface temperature | Southworth 2010 |
| Catalog stellar effective temperature | 6,091 [+10 / -10] | K | Stassun et al. 2017 |
| Catalog stellar radius | 1.19 [+0.02 / -0.02] | Solar radii | Stassun et al. 2017 |
| Catalog stellar mass | 1.23 [+0.09 / -0.09] | Solar masses | Stassun et al. 2017 |
| Catalog stellar luminosity | 0.23086 [+0.015 / -0.0123] | log10 Solar luminosity | Barstow et al. 2017 |
| Catalog stellar age | 3.1 [+0.8 / -0.7] | Gyr | Kokori et al. 2023 |
| Catalog stellar metallicity | 0.01 | dex | Stassun et al. 2017 |
| System distance | 48.302 [+0.124 / -0.1234] | pc | TICv8 |
What about life?
Likely a deep gaseous envelope, without a solid exterior surface. Atmospheric or moon life is speculative; this is not proof that all life is impossible. No confirmed life; no planet-specific biosignature literature review in this release.
Papers and references
Henry et al. 2000 · Stassun et al. 2017 · Southworth 2010 · Bonomo et al. 2017 · ExoFOP · Barstow et al. 2017 · Kokori et al. 2023 · TICv8