Kepler-185 b
Astrophysical Synthesis & Habitability Characterization
Kepler-185 b is a confirmed terrestrial 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 0.0177% across the stellar disk), this world measures 1.17 Earth radii and has a measured mass of 1.71 Earth masses. Combining its mass and radius yields a mean bulk density of 5.89 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.25 g⊕ (12.26 m/s²), and an escape velocity of 13.5 km/s.
In its orbital architecture around Kepler-185, Kepler-185 b completes one full revolution every 1.633 Earth days at a semi-major axis of 0.026 AU (an ultra-close orbit less than one-seventh of Mercury's 0.387 AU distance from the Sun, where strong stellar tidal forces typically induce synchronous rotation). Its mean orbital velocity is approximately 173.2 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 1237 K (+964°C / +1767°F) and receiving 475.51 S⊕ (~647,165 W/m²), Kepler-185 b 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 b sharing its stellar neighborhood alongside Kepler-185 c.
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) | 0.026000 AU |
| Orbital Period | 1.633 days |
| Mean Orbital Velocity | 173.2 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.0400° |
| Mean Bulk Density | 5.89 g/cm³ (13.5 km/s vesc) |
| Insolation Flux | 475.5070 S⊕ (~647,165 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1522.300 LY (466.735 pc) |