Kepler-1371 c
Astrophysical Synthesis & Habitability Characterization
Kepler-1371 c is a confirmed sub-earth exoplanet orbiting the star Kepler-1371, located approximately 1680.8 light-years (515.33 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.005% across the stellar disk), this world measures 0.64 Earth radii and has a measured mass of 0.196 Earth masses. Combining its mass and radius yields a mean bulk density of 4.12 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 0.48 g⊕ (4.71 m/s²), and an escape velocity of 6.2 km/s.
In its orbital architecture around Kepler-1371, Kepler-1371 c completes one full revolution every 2.005 Earth days at a semi-major axis of 0.02937 AU (an ultra-close orbit less than one-seventh of Mercury's 0.387 AU distance from the Sun, where strong stellar tidal forces typically induce synchronous rotation). Its mean orbital velocity is approximately 159.3 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 1216 K (+943°C / +1729°F) and receiving 853.27 S⊕ (~1,161,299 W/m²), Kepler-1371 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-1371 is classified as a stellar host with an effective photospheric temperature of 5,361 K, a radius of 0.83 R☉, a mass of 0.87 M☉, an estimated bolometric luminosity of 0.511 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.37 Gyr and a metallicity of [Fe/H] = -0.07 dex (near-solar heavy-element abundance). From Earth, Kepler-1371 shines at apparent V-band magnitude 14.018 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-1371 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-1371 c sharing its stellar neighborhood alongside Kepler-1371 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-1371 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,361 K |
| Stellar Radius | 0.8300 R☉ |
| Stellar Mass | 0.8700 M☉ |
| Bolometric Luminosity | 0.511 L☉ |
| Metallicity [Fe/H] | -0.070 dex |
| Stellar Age | 4.370 Gyr |
| Apparent Magnitude | V: 14.018 · G: 13.834 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.029370 AU |
| Orbital Period | 2.005 days |
| Mean Orbital Velocity | 159.3 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 77.6600° |
| Mean Bulk Density | 4.12 g/cm³ (6.2 km/s vesc) |
| Insolation Flux | 853.2690 S⊕ (~1,161,299 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1680.800 LY (515.334 pc) |