Kepler-146 b
Astrophysical Synthesis & Habitability Characterization
Kepler-146 b 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 0.0793% across the stellar disk), this world measures 3.71 Earth radii (0.33 Jupiter radii) and has a measured mass of 13.3 Earth masses. Combining its mass and radius yields a mean bulk density of 1.44 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.97 g⊕ (9.51 m/s²), and an escape velocity of 21.2 km/s.
In its orbital architecture around Kepler-146, Kepler-146 b completes one full revolution every 31.159 Earth days at a semi-major axis of 0.2 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 69.8 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 639 K (+366°C / +691°F) and receiving 32.89 S⊕ (~44,763 W/m²), Kepler-146 b 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 b sharing its stellar neighborhood alongside Kepler-146 c.
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) | 0.200000 AU |
| Orbital Period | 31.159 days |
| Mean Orbital Velocity | 69.8 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.9700° |
| Mean Bulk Density | 1.44 g/cm³ (21.2 km/s vesc) |
| Insolation Flux | 32.8900 S⊕ (~44,763 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2337.900 LY (716.797 pc) |