Kepler-1266 b
Astrophysical Synthesis & Habitability Characterization
Kepler-1266 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-1266, located approximately 2770.1 light-years (849.31 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0969% across the stellar disk), this world measures 2.58 Earth radii and has a measured mass of 7.18 Earth masses. Combining its mass and radius yields a mean bulk density of 2.31 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.08 g⊕ (10.59 m/s²), and an escape velocity of 18.7 km/s.
In its orbital architecture around Kepler-1266, Kepler-1266 b completes one full revolution every 28.475 Earth days at a semi-major axis of 0.16431 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 62.8 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 489 K (+216°C / +421°F) and receiving 10.31 S⊕ (~14,036 W/m²), Kepler-1266 b 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 5,044 K, a radius of 0.76 R☉, a mass of 0.8 M☉, an estimated bolometric luminosity of 0.335 L☉. Stellar evolution modeling indicates an estimated stellar age of 5.13 Gyr and a metallicity of [Fe/H] = -0.07 dex (near-solar heavy-element abundance). 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 b sharing its stellar neighborhood alongside Kepler-1266 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-1266 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,044 K |
| Stellar Radius | 0.7600 R☉ |
| Stellar Mass | 0.8000 M☉ |
| Bolometric Luminosity | 0.335 L☉ |
| Metallicity [Fe/H] | -0.070 dex |
| Stellar Age | 5.130 Gyr |
| Apparent Magnitude | V: 16.016 · G: 15.836 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.164310 AU |
| Orbital Period | 28.475 days |
| Mean Orbital Velocity | 62.8 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 88.2800° |
| Mean Bulk Density | 2.31 g/cm³ (18.7 km/s vesc) |
| Insolation Flux | 10.3130 S⊕ (~14,036 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2770.100 LY (849.312 pc) |