Kepler-246 b
Astrophysical Synthesis & Habitability Characterization
Kepler-246 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-246, located approximately 2042 light-years (626.08 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0666% across the stellar disk), this world measures 2.34 Earth radii and has a measured mass of 6.08 Earth masses. Combining its mass and radius yields a mean bulk density of 2.62 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.11 g⊕ (10.89 m/s²), and an escape velocity of 18 km/s.
In its orbital architecture around Kepler-246, Kepler-246 b completes one full revolution every 4.602 Earth days at a semi-major axis of 0.052 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 122.9 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 896 K (+623°C / +1153°F) and receiving 141.61 S⊕ (~192,735 W/m²), Kepler-246 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-246 is classified as a stellar host with an effective photospheric temperature of 5,206 K, a radius of 0.831 R☉, a mass of 0.853 M☉, an estimated bolometric luminosity of 0.455 L☉. Stellar evolution modeling indicates an estimated stellar age of 1.26 Gyr and a metallicity of [Fe/H] = 0.2 dex (metal-rich relative to the Sun). From Earth, Kepler-246 shines at apparent V-band magnitude 15.197 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-246 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-246 b sharing its stellar neighborhood alongside Kepler-246 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-246 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,206 K |
| Stellar Radius | 0.8310 R☉ |
| Stellar Mass | 0.8530 M☉ |
| Bolometric Luminosity | 0.455 L☉ |
| Metallicity [Fe/H] | 0.200 dex |
| Stellar Age | 1.260 Gyr |
| Apparent Magnitude | V: 15.197 · G: 15.042 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.052000 AU |
| Orbital Period | 4.602 days |
| Mean Orbital Velocity | 122.9 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 87.5600° |
| Mean Bulk Density | 2.62 g/cm³ (18 km/s vesc) |
| Insolation Flux | 141.6130 S⊕ (~192,735 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2042.000 LY (626.078 pc) |