Kepler-311 c
Astrophysical Synthesis & Habitability Characterization
Kepler-311 c is a confirmed super-earth exoplanet orbiting the star Kepler-311, located approximately 2539.6 light-years (778.65 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0122% across the stellar disk), this world measures 1.43 Earth radii and has a measured mass of 2.63 Earth masses. Combining its mass and radius yields a mean bulk density of 4.96 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.29 g⊕ (12.65 m/s²), and an escape velocity of 15.2 km/s.
In its orbital architecture around Kepler-311, Kepler-311 c completes one full revolution every 19.738 Earth days at a semi-major axis of 0.145 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 79.9 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 744 K (+471°C / +880°F) and receiving 72.46 S⊕ (~98,613 W/m²), Kepler-311 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-311 is classified as a stellar host with an effective photospheric temperature of 5,905 K, a radius of 1.188 R☉, a mass of 0.994 M☉, an estimated bolometric luminosity of 1.54 L☉. Stellar evolution modeling indicates an estimated stellar age of 1.95 Gyr and a metallicity of [Fe/H] = -0.03 dex (near-solar heavy-element abundance). From Earth, Kepler-311 shines at apparent V-band magnitude 13.902 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-311 system is a multi-planet architecture hosting 3 confirmed worlds, with Kepler-311 c sharing its stellar neighborhood alongside Kepler-311 b, Kepler-311 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-311 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,905 K |
| Stellar Radius | 1.1880 R☉ |
| Stellar Mass | 0.9940 M☉ |
| Bolometric Luminosity | 1.54 L☉ |
| Metallicity [Fe/H] | -0.030 dex |
| Stellar Age | 1.950 Gyr |
| Apparent Magnitude | V: 13.902 · G: 13.754 |
| System Architecture | 1 Star, 3 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.145000 AU |
| Orbital Period | 19.738 days |
| Mean Orbital Velocity | 79.9 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 88.0600° |
| Mean Bulk Density | 4.96 g/cm³ (15.2 km/s vesc) |
| Insolation Flux | 72.4560 S⊕ (~98,613 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2539.600 LY (778.654 pc) |