Kepler-247 b
Astrophysical Synthesis & Habitability Characterization
Kepler-247 b is a confirmed super-earth exoplanet orbiting the star Kepler-247, located approximately 2164.7 light-years (663.71 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0383% across the stellar disk), this world measures 1.64 Earth radii and has a measured mass of 3.33 Earth masses. Combining its mass and radius yields a mean bulk density of 4.16 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.24 g⊕ (12.16 m/s²), and an escape velocity of 15.9 km/s.
In its orbital architecture around Kepler-247, Kepler-247 b completes one full revolution every 3.336 Earth days at a semi-major axis of 0.042 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 137 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 970 K (+697°C / +1287°F) and receiving 216.11 S⊕ (~294,127 W/m²), Kepler-247 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-247 is classified as an orange K-type star of spectral type K with an effective photospheric temperature of 5,100 K, a radius of 0.768 R☉, a mass of 0.887 M☉, an estimated bolometric luminosity of 0.358 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.14 Gyr and a metallicity of [Fe/H] = 0.3 dex (metal-rich relative to the Sun). From Earth, Kepler-247 shines at apparent V-band magnitude 15.199 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-247 system is a multi-planet architecture hosting 4 confirmed worlds, with Kepler-247 b sharing its stellar neighborhood alongside Kepler-247 c, Kepler-247 d, KOI-884 e.
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-247 |
| Spectral Type | K |
| Effective Temp (Teff) | 5,100 K |
| Stellar Radius | 0.7680 R☉ |
| Stellar Mass | 0.8870 M☉ |
| Bolometric Luminosity | 0.358 L☉ |
| Metallicity [Fe/H] | 0.300 dex |
| Stellar Age | 2.140 Gyr |
| Apparent Magnitude | V: 15.199 · G: 15.047 |
| System Architecture | 1 Star, 4 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.042000 AU |
| Orbital Period | 3.336 days |
| Mean Orbital Velocity | 137 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 88.8800° |
| Mean Bulk Density | 4.16 g/cm³ (15.9 km/s vesc) |
| Insolation Flux | 216.1110 S⊕ (~294,127 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2164.700 LY (663.711 pc) |