Kepler-163 c
Astrophysical Synthesis & Habitability Characterization
Kepler-163 c is a confirmed sub-neptune exoplanet orbiting the star Kepler-163, located approximately 2249.9 light-years (689.81 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0511% across the stellar disk), this world measures 2.26 Earth radii and has a measured mass of 5.73 Earth masses. Combining its mass and radius yields a mean bulk density of 2.74 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 17.8 km/s.
In its orbital architecture around Kepler-163, Kepler-163 c completes one full revolution every 21.347 Earth days at a semi-major axis of 0.152 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 77.5 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 648 K (+375°C / +707°F) and receiving 30.24 S⊕ (~41,154 W/m²), Kepler-163 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-163 is classified as a stellar host with an effective photospheric temperature of 5,776 K, a radius of 0.917 R☉, a mass of 0.882 M☉, an estimated bolometric luminosity of 0.84 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.27 Gyr and a metallicity of [Fe/H] = 0.141 dex (metal-rich relative to the Sun). From Earth, Kepler-163 shines at apparent V-band magnitude 14.467 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-163 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-163 c sharing its stellar neighborhood alongside Kepler-163 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-163 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,776 K |
| Stellar Radius | 0.9170 R☉ |
| Stellar Mass | 0.8820 M☉ |
| Bolometric Luminosity | 0.84 L☉ |
| Metallicity [Fe/H] | 0.141 dex |
| Stellar Age | 4.270 Gyr |
| Apparent Magnitude | V: 14.467 · G: 14.380 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.152000 AU |
| Orbital Period | 21.347 days |
| Mean Orbital Velocity | 77.5 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 87.5000° |
| Mean Bulk Density | 2.74 g/cm³ (17.8 km/s vesc) |
| Insolation Flux | 30.2380 S⊕ (~41,154 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2249.900 LY (689.814 pc) |