Kepler-102 c
Astrophysical Synthesis & Habitability Characterization
Kepler-102 c is a confirmed sub-earth exoplanet orbiting the star Kepler-102, located approximately 351.6 light-years (107.8 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0052% across the stellar disk), this world measures 0.567 Earth radii and has a measured mass of 1.7 Earth masses. Combining its mass and radius yields a mean bulk density of 51.42 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 5.29 g⊕ (51.88 m/s²), and an escape velocity of 19.4 km/s.
In its orbital architecture around Kepler-102, Kepler-102 c completes one full revolution every 7.071 Earth days at a semi-major axis of 0.06702 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 103.1 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.094 carries the world between 0.0607 AU at periapsis and 0.0733 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 777 K (+504°C / +939°F) and receiving 61.00 S⊕ (~83,021 W/m²), Kepler-102 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-102 is classified as a stellar host with an effective photospheric temperature of 4,909 K, a radius of 0.724 R☉, a mass of 0.803 M☉, an estimated bolometric luminosity of 0.273 L☉. Stellar evolution modeling indicates an estimated stellar age of 1.1 Gyr and a metallicity of [Fe/H] = 0.11 dex (metal-rich relative to the Sun). From Earth, Kepler-102 shines at apparent V-band magnitude 12.072 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-102 system is a multi-planet architecture hosting 5 confirmed worlds, with Kepler-102 c sharing its stellar neighborhood alongside Kepler-102 b, Kepler-102 d, Kepler-102 e, Kepler-102 f.
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-102 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 4,909 K |
| Stellar Radius | 0.7240 R☉ |
| Stellar Mass | 0.8030 M☉ |
| Bolometric Luminosity | 0.273 L☉ |
| Metallicity [Fe/H] | 0.110 dex |
| Stellar Age | 1.100 Gyr |
| Apparent Magnitude | V: 12.072 · G: 11.478 |
| System Architecture | 1 Star, 5 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.067020 AU |
| Orbital Period | 7.071 days |
| Mean Orbital Velocity | 103.1 km/s |
| Orbital Eccentricity (e) | 0.09400 |
| Orbital Inclination (i) | 89.8200° |
| Mean Bulk Density | 51.42 g/cm³ (19.4 km/s vesc) |
| Insolation Flux | 61.0000 S⊕ (~83,021 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 351.600 LY (107.796 pc) |