Kepler-1266 c
Astrophysical Synthesis & Habitability Characterization
Kepler-1266 c is a confirmed super-earth exoplanet orbiting the star Kepler-1266, located approximately 2770.1 light-years (849.31 parsecs) from the Solar System. First announced in 2021 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0344% across the stellar disk), this world measures 1.68 Earth radii and has a measured mass of 3.46 Earth masses. Combining its mass and radius yields a mean bulk density of 4.02 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.23 g⊕ (12.06 m/s²), and an escape velocity of 16.1 km/s.
In its orbital architecture around Kepler-1266, Kepler-1266 c completes one full revolution every 4.866 Earth days at a semi-major axis of 0.0506 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 113.1 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 881 K (+608°C / +1126°F) and receiving 110.40 S⊕ (~150,254 W/m²), Kepler-1266 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-1266 is classified as a stellar host with an effective photospheric temperature of 4,996 K, a radius of 0.831 R☉, a mass of 0.791 M☉, an estimated bolometric luminosity of 0.386 L☉. Stellar evolution modeling indicates an estimated stellar age of 7.24 Gyr and a metallicity of [Fe/H] = 0.14 dex (metal-rich relative to the Sun). From Earth, Kepler-1266 shines at apparent V-band magnitude 16.016 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-1266 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-1266 c sharing its stellar neighborhood alongside Kepler-1266 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-1266 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 4,996 K |
| Stellar Radius | 0.8310 R☉ |
| Stellar Mass | 0.7910 M☉ |
| Bolometric Luminosity | 0.386 L☉ |
| Metallicity [Fe/H] | 0.140 dex |
| Stellar Age | 7.240 Gyr |
| Apparent Magnitude | V: 16.016 · G: 15.836 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.050600 AU |
| Orbital Period | 4.866 days |
| Mean Orbital Velocity | 113.1 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 84.7300° |
| Mean Bulk Density | 4.02 g/cm³ (16.1 km/s vesc) |
| Insolation Flux | 110.4000 S⊕ (~150,254 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2770.100 LY (849.312 pc) |