Kepler-146 c
Astrophysical Synthesis & Habitability Characterization
Kepler-146 c is a confirmed sub-neptune exoplanet orbiting the star Kepler-146, located approximately 2337.9 light-years (716.8 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0564% across the stellar disk), this world measures 3.13 Earth radii (0.28 Jupiter radii) and has a measured mass of 9.96 Earth masses. Combining its mass and radius yields a mean bulk density of 1.79 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.02 g⊕ (10 m/s²), and an escape velocity of 20 km/s.
In its orbital architecture around Kepler-146, Kepler-146 c completes one full revolution every 76.732 Earth days at a semi-major axis of 0.364 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 51.6 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 473 K (+200°C / +392°F) and receiving 9.89 S⊕ (~13,456 W/m²), Kepler-146 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-146 is classified as a stellar host with an effective photospheric temperature of 5,948 K, a radius of 1.208 R☉, a mass of 1.079 M☉, an estimated bolometric luminosity of 1.639 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.91 Gyr and a metallicity of [Fe/H] = -0.026 dex (near-solar heavy-element abundance). From Earth, Kepler-146 shines at apparent V-band magnitude 13.921 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-146 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-146 c sharing its stellar neighborhood alongside Kepler-146 b.
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-146 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,948 K |
| Stellar Radius | 1.2080 R☉ |
| Stellar Mass | 1.0790 M☉ |
| Bolometric Luminosity | 1.639 L☉ |
| Metallicity [Fe/H] | -0.026 dex |
| Stellar Age | 0.910 Gyr |
| Apparent Magnitude | V: 13.921 · G: 13.803 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.364000 AU |
| Orbital Period | 76.732 days |
| Mean Orbital Velocity | 51.6 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.6900° |
| Mean Bulk Density | 1.79 g/cm³ (20 km/s vesc) |
| Insolation Flux | 9.8870 S⊕ (~13,456 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2337.900 LY (716.797 pc) |