Kepler-1031 b
Astrophysical Synthesis & Habitability Characterization
Kepler-1031 b is a confirmed terrestrial exoplanet orbiting the star Kepler-1031, located approximately 2227.3 light-years (682.88 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0051% across the stellar disk), this world measures 0.87 Earth radii and has a measured mass of 0.59 Earth masses. Combining its mass and radius yields a mean bulk density of 4.94 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 0.78 g⊕ (7.65 m/s²), and an escape velocity of 9.2 km/s.
In its orbital architecture around Kepler-1031, Kepler-1031 b completes one full revolution every 1.226 Earth days at a semi-major axis of 0.0218 AU (an ultra-close orbit less than one-seventh of Mercury's 0.387 AU distance from the Sun, where strong stellar tidal forces typically induce synchronous rotation). Its mean orbital velocity is approximately 193.4 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 2024 K (+1751°C / +3184°F) and receiving 3,973.86 S⊕ (~5,408,423 W/m²), Kepler-1031 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-1031 is classified as a stellar host with an effective photospheric temperature of 6,011 K, a radius of 1.12 R☉, a mass of 1.09 M☉, an estimated bolometric luminosity of 1.469 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.39 Gyr and a metallicity of [Fe/H] = 0.03 dex (near-solar heavy-element abundance). From Earth, Kepler-1031 shines at apparent V-band magnitude 13.877 (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-1031 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,011 K |
| Stellar Radius | 1.1200 R☉ |
| Stellar Mass | 1.0900 M☉ |
| Bolometric Luminosity | 1.469 L☉ |
| Metallicity [Fe/H] | 0.030 dex |
| Stellar Age | 3.390 Gyr |
| Apparent Magnitude | V: 13.877 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.021800 AU |
| Orbital Period | 1.226 days |
| Mean Orbital Velocity | 193.4 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.9300° |
| Mean Bulk Density | 4.94 g/cm³ (9.2 km/s vesc) |
| Insolation Flux | 3973.8600 S⊕ (~5,408,423 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2227.300 LY (682.882 pc) |