K2-185 c
Astrophysical Synthesis & Habitability Characterization
K2-185 c is a confirmed sub-neptune exoplanet orbiting the star K2-185, located approximately 875.3 light-years (268.36 parsecs) from the Solar System. First announced in 2018 by K2 using the Transit detection technique (producing an estimated primary transit depth of 0.0543% across the stellar disk), this world measures 2.39 Earth radii and has a measured mass of 6.3 Earth masses. Combining its mass and radius yields a mean bulk density of 2.54 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.1 g⊕ (10.79 m/s²), and an escape velocity of 18.2 km/s.
In its orbital architecture around K2-185, K2-185 c completes one full revolution every 52.713 Earth days.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 477 K (+204°C / +399°F), K2-185 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star K2-185 is classified as a stellar host with an effective photospheric temperature of 5,788 K, a radius of 0.94 R☉, a mass of 0.96 M☉, an estimated bolometric luminosity of 0.89 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.1 dex (near-solar heavy-element abundance). From Earth, K2-185 shines at apparent V-band magnitude 12.235 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The K2-185 system is a multi-planet architecture hosting 2 confirmed worlds, with K2-185 c sharing its stellar neighborhood alongside K2-185 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: K2 · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | K2-185 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,788 K |
| Stellar Radius | 0.9400 R☉ |
| Stellar Mass | 0.9600 M☉ |
| Bolometric Luminosity | 0.89 L☉ |
| Metallicity [Fe/H] | -0.100 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 12.235 · G: 12.064 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | — |
| Orbital Period | 52.713 days |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 89.0026° |
| Mean Bulk Density | 2.54 g/cm³ (18.2 km/s vesc) |
| Insolation Flux | — |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 875.300 LY (268.357 pc) |