Kepler-400 c
Astrophysical Synthesis & Habitability Characterization
Kepler-400 c is a confirmed super-earth exoplanet orbiting the star Kepler-400, located approximately 2759.2 light-years (845.97 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0142% across the stellar disk), this world measures 1.49 Earth radii and has a measured mass of 2.83 Earth masses. Combining its mass and radius yields a mean bulk density of 4.72 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.27 g⊕ (12.45 m/s²), and an escape velocity of 15.4 km/s.
In its orbital architecture around Kepler-400, Kepler-400 c completes one full revolution every 17.341 Earth days at a semi-major axis of 0.134 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 84.1 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 755 K (+482°C / +900°F) and receiving 76.86 S⊕ (~104,606 W/m²), Kepler-400 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-400 is classified as a stellar host with an effective photospheric temperature of 5,886 K, a radius of 1.145 R☉, a mass of 1.08 M☉, an estimated bolometric luminosity of 1.412 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.63 Gyr and a metallicity of [Fe/H] = 0.084 dex (metal-rich relative to the Sun). From Earth, Kepler-400 shines at apparent V-band magnitude 13.762 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-400 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-400 c sharing its stellar neighborhood alongside Kepler-400 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-400 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,886 K |
| Stellar Radius | 1.1450 R☉ |
| Stellar Mass | 1.0800 M☉ |
| Bolometric Luminosity | 1.412 L☉ |
| Metallicity [Fe/H] | 0.084 dex |
| Stellar Age | 3.630 Gyr |
| Apparent Magnitude | V: 13.762 · G: 13.840 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.134000 AU |
| Orbital Period | 17.341 days |
| Mean Orbital Velocity | 84.1 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.1900° |
| Mean Bulk Density | 4.72 g/cm³ (15.4 km/s vesc) |
| Insolation Flux | 76.8600 S⊕ (~104,606 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2759.200 LY (845.970 pc) |