Kepler-111 c
Astrophysical Synthesis & Habitability Characterization
Kepler-111 c is a confirmed gas giant exoplanet orbiting the star Kepler-111, located approximately 2143.6 light-years (657.22 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.3217% across the stellar disk), this world measures 7.084 Earth radii (0.63 Jupiter radii) and has a measured mass of 222.48 Earth masses (0.7 Jupiter masses). Combining its mass and radius yields a mean bulk density of 3.45 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 4.43 g⊕ (43.44 m/s²), and an escape velocity of 62.7 km/s.
In its orbital architecture around Kepler-111, Kepler-111 c completes one full revolution every 224.778 Earth days at a semi-major axis of 0.751 AU (comparable to the inner terrestrial zone between Venus, Earth at 1.00 AU, and Mars at 1.52 AU). Its mean orbital velocity is approximately 36.3 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.176 carries the world between 0.6188 AU at periapsis and 0.8832 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 352 K (+79°C / +174°F) and receiving 2.48 S⊕ (~3,375 W/m²), Kepler-111 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-111 is classified as a stellar host with an effective photospheric temperature of 5,914 K, a radius of 1.145 R☉, a mass of 1.118 M☉, an estimated bolometric luminosity of 1.439 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.4 Gyr and a metallicity of [Fe/H] = 0.237 dex (metal-rich relative to the Sun). From Earth, Kepler-111 shines at apparent V-band magnitude 13.543 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-111 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-111 c sharing its stellar neighborhood alongside Kepler-111 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-111 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,914 K |
| Stellar Radius | 1.1450 R☉ |
| Stellar Mass | 1.1180 M☉ |
| Bolometric Luminosity | 1.439 L☉ |
| Metallicity [Fe/H] | 0.237 dex |
| Stellar Age | 3.400 Gyr |
| Apparent Magnitude | V: 13.543 · G: 13.419 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.751000 AU |
| Orbital Period | 224.778 days |
| Mean Orbital Velocity | 36.3 km/s |
| Orbital Eccentricity (e) | 0.17600 |
| Orbital Inclination (i) | 89.7560° |
| Mean Bulk Density | 3.45 g/cm³ (62.7 km/s vesc) |
| Insolation Flux | 2.4800 S⊕ (~3,375 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2143.600 LY (657.223 pc) |