Kepler-168 c
Astrophysical Synthesis & Habitability Characterization
Kepler-168 c is a confirmed sub-neptune exoplanet orbiting the star Kepler-168, located approximately 4382.2 light-years (1343.6 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0496% across the stellar disk), this world measures 2.69 Earth radii and has a measured mass of 7.7 Earth masses. Combining its mass and radius yields a mean bulk density of 2.18 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.06 g⊕ (10.4 m/s²), and an escape velocity of 18.9 km/s.
In its orbital architecture around Kepler-168, Kepler-168 c completes one full revolution every 13.193 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 95.7 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 862 K (+589°C / +1092°F) and receiving 169.00 S⊕ (~230,012 W/m²), Kepler-168 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-168 is classified as a stellar host with an effective photospheric temperature of 6,282 K, a radius of 1.107 R☉, a mass of 1.113 M☉, an estimated bolometric luminosity of 1.712 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.29 Gyr and a metallicity of [Fe/H] = 0.09 dex (metal-rich relative to the Sun). From Earth, Kepler-168 shines at apparent V-band magnitude 14.842 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-168 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-168 c sharing its stellar neighborhood alongside Kepler-168 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-168 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,282 K |
| Stellar Radius | 1.1070 R☉ |
| Stellar Mass | 1.1130 M☉ |
| Bolometric Luminosity | 1.712 L☉ |
| Metallicity [Fe/H] | 0.090 dex |
| Stellar Age | 2.290 Gyr |
| Apparent Magnitude | V: 14.842 · G: 14.605 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.116000 AU |
| Orbital Period | 13.193 days |
| Mean Orbital Velocity | 95.7 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.9900° |
| Mean Bulk Density | 2.18 g/cm³ (18.9 km/s vesc) |
| Insolation Flux | 169.0020 S⊕ (~230,012 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 4382.200 LY (1343.600 pc) |