Kepler-1311 b
Astrophysical Synthesis & Habitability Characterization
Kepler-1311 b is a confirmed terrestrial exoplanet orbiting the star Kepler-1311, located approximately 2825.6 light-years (866.33 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0066% across the stellar disk), this world measures 1.24 Earth radii and has a measured mass of 2.07 Earth masses. Combining its mass and radius yields a mean bulk density of 5.99 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.35 g⊕ (13.24 m/s²), and an escape velocity of 14.5 km/s.
In its orbital architecture around Kepler-1311, Kepler-1311 b completes one full revolution every 11.173 Earth days at a semi-major axis of 0.10082 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 98.2 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 1019 K (+746°C / +1375°F) and receiving 296.92 S⊕ (~404,108 W/m²), Kepler-1311 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-1311 is classified as a stellar host with an effective photospheric temperature of 5,748 K, a radius of 1.4 R☉, a mass of 1.05 M☉, an estimated bolometric luminosity of 1.92 L☉. Stellar evolution modeling indicates an estimated stellar age of 7.59 Gyr and a metallicity of [Fe/H] = 0.09 dex (metal-rich relative to the Sun). From Earth, Kepler-1311 shines at apparent V-band magnitude 13.528 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-1311 system is a multi-planet architecture hosting 3 confirmed worlds, with Kepler-1311 b sharing its stellar neighborhood alongside Kepler-1311 c, Kepler-1311 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-1311 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,748 K |
| Stellar Radius | 1.4000 R☉ |
| Stellar Mass | 1.0500 M☉ |
| Bolometric Luminosity | 1.92 L☉ |
| Metallicity [Fe/H] | 0.090 dex |
| Stellar Age | 7.590 Gyr |
| Apparent Magnitude | V: 13.528 · G: 13.318 |
| System Architecture | 1 Star, 3 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.100820 AU |
| Orbital Period | 11.173 days |
| Mean Orbital Velocity | 98.2 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 87.6400° |
| Mean Bulk Density | 5.99 g/cm³ (14.5 km/s vesc) |
| Insolation Flux | 296.9200 S⊕ (~404,108 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2825.600 LY (866.331 pc) |