Kepler-116 c
Astrophysical Synthesis & Habitability Characterization
Kepler-116 c is a confirmed sub-neptune exoplanet orbiting the star Kepler-116, located approximately 3115.3 light-years (955.17 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.021% across the stellar disk), this world measures 2.3 Earth radii and has a measured mass of 5.9 Earth masses. Combining its mass and radius yields a mean bulk density of 2.67 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.12 g⊕ (10.98 m/s²), and an escape velocity of 17.9 km/s.
In its orbital architecture around Kepler-116, Kepler-116 c completes one full revolution every 13.072 Earth days at a semi-major axis of 0.116 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 96.5 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 964 K (+691°C / +1276°F) and receiving 208.98 S⊕ (~284,425 W/m²), Kepler-116 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-116 is classified as a stellar host with an effective photospheric temperature of 6,142 K, a radius of 1.454 R☉, a mass of 1.198 M☉, an estimated bolometric luminosity of 2.699 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.16 Gyr and a metallicity of [Fe/H] = 0.07 dex (metal-rich relative to the Sun). From Earth, Kepler-116 shines at apparent V-band magnitude 13.744 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-116 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-116 c sharing its stellar neighborhood alongside Kepler-116 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-116 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,142 K |
| Stellar Radius | 1.4540 R☉ |
| Stellar Mass | 1.1980 M☉ |
| Bolometric Luminosity | 2.699 L☉ |
| Metallicity [Fe/H] | 0.070 dex |
| Stellar Age | 3.160 Gyr |
| Apparent Magnitude | V: 13.744 · G: 13.689 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.116000 AU |
| Orbital Period | 13.072 days |
| Mean Orbital Velocity | 96.5 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 88.0500° |
| Mean Bulk Density | 2.67 g/cm³ (17.9 km/s vesc) |
| Insolation Flux | 208.9820 S⊕ (~284,425 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 3115.300 LY (955.168 pc) |