Kepler-56 c
Astrophysical Synthesis & Habitability Characterization
Kepler-56 c is a confirmed gas giant exoplanet orbiting the star Kepler-56, located approximately 2977.8 light-years (912.99 parsecs) from the Solar System. First announced in 2012 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0451% across the stellar disk), this world measures 9.8 Earth radii (0.87 Jupiter radii) and has a measured mass of 181 Earth masses (0.57 Jupiter masses). Combining its mass and radius yields a mean bulk density of 1.06 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.88 g⊕ (18.44 m/s²), and an escape velocity of 48.1 km/s.
In its orbital architecture around Kepler-56, Kepler-56 c completes one full revolution every 21.402 Earth days at a semi-major axis of 0.1652 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 84 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 1087 K (+814°C / +1497°F) and receiving 317.21 S⊕ (~431,717 W/m²), Kepler-56 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-56 is classified as a stellar host with an effective photospheric temperature of 4,840 K, a radius of 4.23 R☉, a mass of 1.32 M☉, an estimated bolometric luminosity of 8.81 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.5 Gyr and a metallicity of [Fe/H] = 0.2 dex (metal-rich relative to the Sun). From Earth, Kepler-56 shines at apparent V-band magnitude 12.598 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-56 system is a multi-planet architecture hosting 3 confirmed worlds, with Kepler-56 c sharing its stellar neighborhood alongside Kepler-56 b, Kepler-56 d.
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-56 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 4,840 K |
| Stellar Radius | 4.2300 R☉ |
| Stellar Mass | 1.3200 M☉ |
| Bolometric Luminosity | 8.81 L☉ |
| Metallicity [Fe/H] | 0.200 dex |
| Stellar Age | 3.500 Gyr |
| Apparent Magnitude | V: 12.598 · G: 12.430 |
| System Architecture | 1 Star, 3 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.165200 AU |
| Orbital Period | 21.402 days |
| Mean Orbital Velocity | 84 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 80.4000° |
| Mean Bulk Density | 1.06 g/cm³ (48.1 km/s vesc) |
| Insolation Flux | 317.2060 S⊕ (~431,717 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2977.800 LY (912.994 pc) |