Kepler-864 c
Astrophysical Synthesis & Habitability Characterization
Kepler-864 c is a confirmed super-earth exoplanet orbiting the star Kepler-864, located approximately 6597.8 light-years (2022.9 parsecs) from the Solar System. First announced in 2023 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0154% across the stellar disk), this world measures 1.62 Earth radii and has a measured mass of 3.26 Earth masses. Combining its mass and radius yields a mean bulk density of 4.23 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.24 g⊕ (12.16 m/s²), and an escape velocity of 15.9 km/s.
In its orbital architecture around Kepler-864, Kepler-864 c completes one full revolution every 2.422 Earth days at a semi-major axis of 0.0382 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 171.6 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 1532 K (+1259°C / +2298°F) and receiving 1,305.04 S⊕ (~1,776,159 W/m²), Kepler-864 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-864 is classified as a stellar host with an effective photospheric temperature of 6,213 K, a radius of 1.195 R☉, a mass of 1.27 M☉, an estimated bolometric luminosity of 1.909 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.3 Gyr and a metallicity of [Fe/H] = 0.36 dex (metal-rich relative to the Sun). From Earth, Kepler-864 shines at apparent V-band magnitude 15.898 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-864 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-864 c sharing its stellar neighborhood alongside Kepler-864 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-864 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,213 K |
| Stellar Radius | 1.1950 R☉ |
| Stellar Mass | 1.2700 M☉ |
| Bolometric Luminosity | 1.909 L☉ |
| Metallicity [Fe/H] | 0.360 dex |
| Stellar Age | 0.300 Gyr |
| Apparent Magnitude | V: 15.898 · G: 15.782 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.038200 AU |
| Orbital Period | 2.422 days |
| Mean Orbital Velocity | 171.6 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 84.1100° |
| Mean Bulk Density | 4.23 g/cm³ (15.9 km/s vesc) |
| Insolation Flux | 1305.0400 S⊕ (~1,776,159 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 6597.800 LY (2022.900 pc) |