Kepler-831 b
Astrophysical Synthesis & Habitability Characterization
Kepler-831 b is a confirmed super-earth exoplanet orbiting the star Kepler-831, located approximately 1935.9 light-years (593.54 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0144% across the stellar disk), this world measures 1.27 Earth radii and has a measured mass of 2.15 Earth masses. Combining its mass and radius yields a mean bulk density of 5.79 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.33 g⊕ (13.04 m/s²), and an escape velocity of 14.6 km/s.
In its orbital architecture around Kepler-831, Kepler-831 b completes one full revolution every 5.622 Earth days at a semi-major axis of 0.05984 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 115.8 km/s (compared to Earth's 29.8 km/s). The orbit is modeled as circular (e = 0.00), maintaining a constant stellar distance throughout its year.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 992 K (+719°C / +1326°F) and receiving 266.25 S⊕ (~362,365 W/m²), Kepler-831 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-831 is classified as a stellar host with an effective photospheric temperature of 5,732 K, a radius of 0.97 R☉, a mass of 0.99 M☉, an estimated bolometric luminosity of 0.911 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.17 Gyr and a metallicity of [Fe/H] = 0.02 dex (near-solar heavy-element abundance). From Earth, Kepler-831 shines at apparent V-band magnitude 13.751 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.
Methodology: Computed using the Schulze-Makuch et al. (2011) weighted metric comparing physical interior (radius, estimated density) and surface thermal regime (escape velocity, equilibrium temperature).
Discovery Facility: Kepler · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | Kepler-831 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,732 K |
| Stellar Radius | 0.9700 R☉ |
| Stellar Mass | 0.9900 M☉ |
| Bolometric Luminosity | 0.911 L☉ |
| Metallicity [Fe/H] | 0.020 dex |
| Stellar Age | 4.170 Gyr |
| Apparent Magnitude | V: 13.751 · G: 13.631 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.059840 AU |
| Orbital Period | 5.622 days |
| Mean Orbital Velocity | 115.8 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 86.5400° |
| Mean Bulk Density | 5.79 g/cm³ (14.6 km/s vesc) |
| Insolation Flux | 266.2490 S⊕ (~362,365 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1935.900 LY (593.540 pc) |