Kepler-386 c
Astrophysical Synthesis & Habitability Characterization
Kepler-386 c is a confirmed super-earth exoplanet orbiting the star Kepler-386, located approximately 2878.2 light-years (882.46 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0357% across the stellar disk), this world measures 1.58 Earth radii and has a measured mass of 3.12 Earth masses. Combining its mass and radius yields a mean bulk density of 4.36 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.25 g⊕ (12.26 m/s²), and an escape velocity of 15.7 km/s.
In its orbital architecture around Kepler-386, Kepler-386 c completes one full revolution every 25.193 Earth days at a semi-major axis of 0.155 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 66.9 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 513 K (+240°C / +464°F) and receiving 16.66 S⊕ (~22,670 W/m²), Kepler-386 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-386 is classified as a stellar host with an effective photospheric temperature of 5,178 K, a radius of 0.767 R☉, a mass of 0.825 M☉, an estimated bolometric luminosity of 0.379 L☉. Stellar evolution modeling indicates an estimated stellar age of 9.9 Gyr and a metallicity of [Fe/H] = 0.07 dex (metal-rich relative to the Sun). From Earth, Kepler-386 shines at apparent V-band magnitude 15.949 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-386 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-386 c sharing its stellar neighborhood alongside Kepler-386 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-386 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,178 K |
| Stellar Radius | 0.7670 R☉ |
| Stellar Mass | 0.8250 M☉ |
| Bolometric Luminosity | 0.379 L☉ |
| Metallicity [Fe/H] | 0.070 dex |
| Stellar Age | 9.900 Gyr |
| Apparent Magnitude | V: 15.949 · G: 15.617 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.155000 AU |
| Orbital Period | 25.193 days |
| Mean Orbital Velocity | 66.9 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 88.7800° |
| Mean Bulk Density | 4.36 g/cm³ (15.7 km/s vesc) |
| Insolation Flux | 16.6570 S⊕ (~22,670 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2878.200 LY (882.462 pc) |