Kepler-466 c
Astrophysical Synthesis & Habitability Characterization
Kepler-466 c is a confirmed terrestrial exoplanet orbiting the star Kepler-466, located approximately 1729 light-years (530.12 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0119% across the stellar disk), this world measures 1.25 Earth radii and has a measured mass of 2.1 Earth masses. Combining its mass and radius yields a mean bulk density of 5.93 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.34 g⊕ (13.14 m/s²), and an escape velocity of 14.5 km/s.
In its orbital architecture around Kepler-466, Kepler-466 c completes one full revolution every 3.709 Earth days at a semi-major axis of 0.04658 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 136.6 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 1206 K (+933°C / +1711°F) and receiving 410.40 S⊕ (~558,554 W/m²), Kepler-466 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-466 is classified as a stellar host with an effective photospheric temperature of 5,927 K, a radius of 1.05 R☉, a mass of 1.04 M☉, an estimated bolometric luminosity of 1.221 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.47 Gyr and a metallicity of [Fe/H] = -0.01 dex (near-solar heavy-element abundance). From Earth, Kepler-466 shines at apparent V-band magnitude 12.799 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-466 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-466 c sharing its stellar neighborhood alongside Kepler-466 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-466 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,927 K |
| Stellar Radius | 1.0500 R☉ |
| Stellar Mass | 1.0400 M☉ |
| Bolometric Luminosity | 1.221 L☉ |
| Metallicity [Fe/H] | -0.010 dex |
| Stellar Age | 3.470 Gyr |
| Apparent Magnitude | V: 12.799 · G: 12.763 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.046580 AU |
| Orbital Period | 3.709 days |
| Mean Orbital Velocity | 136.6 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.7300° |
| Mean Bulk Density | 5.93 g/cm³ (14.5 km/s vesc) |
| Insolation Flux | 410.4000 S⊕ (~558,554 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1729.000 LY (530.122 pc) |