Kepler-1146 b
Astrophysical Synthesis & Habitability Characterization
Kepler-1146 b is a confirmed terrestrial exoplanet orbiting the star Kepler-1146, located approximately 2293 light-years (703.04 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.026% across the stellar disk), this world measures 1.23 Earth radii and has a measured mass of 2.04 Earth masses. Combining its mass and radius yields a mean bulk density of 6.04 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.35 g⊕ (13.24 m/s²), and an escape velocity of 14.4 km/s.
In its orbital architecture around Kepler-1146, Kepler-1146 b completes one full revolution every 2.352 Earth days at a semi-major axis of 0.0325 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 150.3 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 1019 K (+746°C / +1375°F) and receiving 227.96 S⊕ (~310,256 W/m²), Kepler-1146 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-1146 is classified as a stellar host with an effective photospheric temperature of 4,692 K, a radius of 0.7 R☉, a mass of 0.74 M☉, an estimated bolometric luminosity of 0.213 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.9 Gyr and a metallicity of [Fe/H] = -0.06 dex (near-solar heavy-element abundance). From Earth, Kepler-1146 shines at apparent V-band magnitude 15.953 (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-1146 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 4,692 K |
| Stellar Radius | 0.7000 R☉ |
| Stellar Mass | 0.7400 M☉ |
| Bolometric Luminosity | 0.213 L☉ |
| Metallicity [Fe/H] | -0.060 dex |
| Stellar Age | 4.900 Gyr |
| Apparent Magnitude | V: 15.953 · G: 15.850 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.032500 AU |
| Orbital Period | 2.352 days |
| Mean Orbital Velocity | 150.3 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.4800° |
| Mean Bulk Density | 6.04 g/cm³ (14.4 km/s vesc) |
| Insolation Flux | 227.9620 S⊕ (~310,256 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2293.000 LY (703.038 pc) |