Kepler-185 c
Astrophysical Synthesis & Habitability Characterization
Kepler-185 c is a confirmed sub-neptune exoplanet orbiting the star Kepler-185, located approximately 1522.3 light-years (466.74 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0528% across the stellar disk), this world measures 2.02 Earth radii and has a measured mass of 4.74 Earth masses. Combining its mass and radius yields a mean bulk density of 3.17 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.16 g⊕ (11.38 m/s²), and an escape velocity of 17.1 km/s.
In its orbital architecture around Kepler-185, Kepler-185 c completes one full revolution every 20.729 Earth days at a semi-major axis of 0.139 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 73 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 530 K (+257°C / +495°F) and receiving 16.03 S⊕ (~21,815 W/m²), Kepler-185 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-185 is classified as a stellar host with an effective photospheric temperature of 5,208 K, a radius of 0.806 R☉, a mass of 0.763 M☉, an estimated bolometric luminosity of 0.429 L☉. Stellar evolution modeling indicates an estimated stellar age of 11.9 Gyr and a metallicity of [Fe/H] = -0.14 dex (metal-poor relative to the Sun). From Earth, Kepler-185 shines at apparent V-band magnitude 14.562 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-185 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-185 c sharing its stellar neighborhood alongside Kepler-185 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-185 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,208 K |
| Stellar Radius | 0.8060 R☉ |
| Stellar Mass | 0.7630 M☉ |
| Bolometric Luminosity | 0.429 L☉ |
| Metallicity [Fe/H] | -0.140 dex |
| Stellar Age | 11.900 Gyr |
| Apparent Magnitude | V: 14.562 · G: 14.443 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.139000 AU |
| Orbital Period | 20.729 days |
| Mean Orbital Velocity | 73 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.3400° |
| Mean Bulk Density | 3.17 g/cm³ (17.1 km/s vesc) |
| Insolation Flux | 16.0290 S⊕ (~21,815 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1522.300 LY (466.735 pc) |