Kepler-63 b
Astrophysical Synthesis & Habitability Characterization
Kepler-63 b is a confirmed gas giant exoplanet orbiting the star Kepler-63, located approximately 632.9 light-years (194.03 parsecs) from the Solar System. First announced in 2013 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.3865% across the stellar disk), this world measures 6.11 Earth radii (0.55 Jupiter radii) and has a measured mass of 120 Earth masses (0.38 Jupiter masses). Combining its mass and radius yields a mean bulk density of 2.9 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 3.21 g⊕ (31.48 m/s²), and an escape velocity of 49.6 km/s.
In its orbital architecture around Kepler-63, Kepler-63 b completes one full revolution every 9.434 Earth days at a semi-major axis of 0.08 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 92.3 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.45, swinging from 0.044 AU at periapsis out to 0.116 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 791 K (+518°C / +964°F) and receiving 100.37 S⊕ (~136,605 W/m²), Kepler-63 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-63 is classified as a solar-type yellow star of spectral type G5 with an effective photospheric temperature of 5,576 K, a radius of 0.901 R☉, a mass of 0.984 M☉, an estimated bolometric luminosity of 0.704 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.21 Gyr and a metallicity of [Fe/H] = 0.05 dex (near-solar heavy-element abundance). From Earth, Kepler-63 shines at apparent V-band magnitude 12.02 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.
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-63 |
| Spectral Type | G5 |
| Effective Temp (Teff) | 5,576 K |
| Stellar Radius | 0.9010 R☉ |
| Stellar Mass | 0.9840 M☉ |
| Bolometric Luminosity | 0.704 L☉ |
| Metallicity [Fe/H] | 0.050 dex |
| Stellar Age | 0.210 Gyr |
| Apparent Magnitude | V: 12.020 · G: 11.535 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.080000 AU |
| Orbital Period | 9.434 days |
| Mean Orbital Velocity | 92.3 km/s |
| Orbital Eccentricity (e) | 0.45000 |
| Orbital Inclination (i) | 87.8060° |
| Mean Bulk Density | 2.9 g/cm³ (49.6 km/s vesc) |
| Insolation Flux | 100.3710 S⊕ (~136,605 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 632.900 LY (194.033 pc) |