Kepler-126 c
Astrophysical Synthesis & Habitability Characterization
Kepler-126 c is a confirmed super-earth exoplanet orbiting the star Kepler-126, located approximately 774.3 light-years (237.4 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0114% across the stellar disk), this world measures 1.58 Earth radii and has a measured mass of 1.279 Earth masses. Combining its mass and radius yields a mean bulk density of 1.79 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.51 g⊕ (5 m/s²), and an escape velocity of 10.1 km/s.
In its orbital architecture around Kepler-126, Kepler-126 c completes one full revolution every 21.87 Earth days at a semi-major axis of 0.162 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 80.6 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.19 carries the world between 0.1312 AU at periapsis and 0.1928 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 790 K (+517°C / +963°F) and receiving 112.13 S⊕ (~152,606 W/m²), Kepler-126 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-126 is classified as a stellar host with an effective photospheric temperature of 6,239 K, a radius of 1.358 R☉, a mass of 1.108 M☉, an estimated bolometric luminosity of 2.507 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.39 Gyr and a metallicity of [Fe/H] = -0.16 dex (metal-poor relative to the Sun). From Earth, Kepler-126 shines at apparent V-band magnitude 10.505 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-126 system is a multi-planet architecture hosting 3 confirmed worlds, with Kepler-126 c sharing its stellar neighborhood alongside Kepler-126 b, Kepler-126 d.
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-126 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,239 K |
| Stellar Radius | 1.3580 R☉ |
| Stellar Mass | 1.1080 M☉ |
| Bolometric Luminosity | 2.507 L☉ |
| Metallicity [Fe/H] | -0.160 dex |
| Stellar Age | 3.390 Gyr |
| Apparent Magnitude | V: 10.505 · G: 10.454 |
| System Architecture | 1 Star, 3 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.162000 AU |
| Orbital Period | 21.87 days |
| Mean Orbital Velocity | 80.6 km/s |
| Orbital Eccentricity (e) | 0.19000 |
| Orbital Inclination (i) | 88.7500° |
| Mean Bulk Density | 1.79 g/cm³ (10.1 km/s vesc) |
| Insolation Flux | 112.1280 S⊕ (~152,606 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 774.300 LY (237.401 pc) |