Kepler-92 c
Astrophysical Synthesis & Habitability Characterization
Kepler-92 c is a confirmed sub-neptune exoplanet orbiting the star Kepler-92, located approximately 1559 light-years (477.99 parsecs) from the Solar System. First announced in 2013 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0197% across the stellar disk), this world measures 2.6 Earth radii and has a measured mass of 6.1 Earth masses. Combining its mass and radius yields a mean bulk density of 1.91 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.9 g⊕ (8.83 m/s²), and an escape velocity of 17.1 km/s.
In its orbital architecture around Kepler-92, Kepler-92 c completes one full revolution every 26.723 Earth days at a semi-major axis of 0.19054 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 77.6 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.04 (ranging from 0.1829 AU at periapsis to 0.1982 AU at apoapsis), the planet experiences minimal orbital distance variation.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 781 K (+508°C / +946°F) and receiving 106.21 S⊕ (~144,548 W/m²), Kepler-92 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-92 is classified as a stellar host with an effective photospheric temperature of 5,883 K, a radius of 1.7 R☉, a mass of 1.21 M☉, an estimated bolometric luminosity of 3.106 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.98 Gyr and a metallicity of [Fe/H] = 0.138 dex (metal-rich relative to the Sun). From Earth, Kepler-92 shines at apparent V-band magnitude 11.671 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-92 system is a multi-planet architecture hosting 3 confirmed worlds, with Kepler-92 c sharing its stellar neighborhood alongside Kepler-92 b, Kepler-92 d.
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-92 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,883 K |
| Stellar Radius | 1.7000 R☉ |
| Stellar Mass | 1.2100 M☉ |
| Bolometric Luminosity | 3.106 L☉ |
| Metallicity [Fe/H] | 0.138 dex |
| Stellar Age | 3.980 Gyr |
| Apparent Magnitude | V: 11.671 · G: 11.745 |
| System Architecture | 1 Star, 3 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.190540 AU |
| Orbital Period | 26.723 days |
| Mean Orbital Velocity | 77.6 km/s |
| Orbital Eccentricity (e) | 0.04000 |
| Orbital Inclination (i) | 89.9200° |
| Mean Bulk Density | 1.91 g/cm³ (17.1 km/s vesc) |
| Insolation Flux | 106.2070 S⊕ (~144,548 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1559.000 LY (477.992 pc) |