Kepler-271 c
Astrophysical Synthesis & Habitability Characterization
Kepler-271 c is a confirmed terrestrial exoplanet orbiting the star Kepler-271, located approximately 1319.4 light-years (404.54 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.01% across the stellar disk), this world measures 0.95 Earth radii and has a measured mass of 0.809 Earth masses. Combining its mass and radius yields a mean bulk density of 5.2 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 0.9 g⊕ (8.83 m/s²), and an escape velocity of 10.3 km/s.
In its orbital architecture around Kepler-271, Kepler-271 c completes one full revolution every 7.411 Earth days at a semi-major axis of 0.06993 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 102.7 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 850 K (+577°C / +1071°F) and receiving 119.63 S⊕ (~162,818 W/m²), Kepler-271 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-271 is classified as a stellar host with an effective photospheric temperature of 5,555 K, a radius of 0.87 R☉, a mass of 0.9 M☉, an estimated bolometric luminosity of 0.647 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.57 Gyr and a metallicity of [Fe/H] = -0.13 dex (metal-poor relative to the Sun). From Earth, Kepler-271 shines at apparent V-band magnitude 13.578 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-271 system is a multi-planet architecture hosting 3 confirmed worlds, with Kepler-271 c sharing its stellar neighborhood alongside Kepler-271 d, Kepler-271 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-271 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,555 K |
| Stellar Radius | 0.8700 R☉ |
| Stellar Mass | 0.9000 M☉ |
| Bolometric Luminosity | 0.647 L☉ |
| Metallicity [Fe/H] | -0.130 dex |
| Stellar Age | 4.570 Gyr |
| Apparent Magnitude | V: 13.578 · G: 13.428 |
| System Architecture | 1 Star, 3 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.069930 AU |
| Orbital Period | 7.411 days |
| Mean Orbital Velocity | 102.7 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.7900° |
| Mean Bulk Density | 5.2 g/cm³ (10.3 km/s vesc) |
| Insolation Flux | 119.6310 S⊕ (~162,818 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1319.400 LY (404.542 pc) |