Kepler-16 b
Astrophysical Synthesis & Habitability Characterization
Kepler-16 b is a confirmed gas giant exoplanet orbiting the star Kepler-16, located approximately 244.9 light-years (75.09 parsecs) from the Solar System. First announced in 2011 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 1.4249% across the stellar disk), this world measures 8.449 Earth radii (0.75 Jupiter radii) and has a measured mass of 105.833 Earth masses (0.33 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.97 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.48 g⊕ (14.51 m/s²), and an escape velocity of 39.6 km/s.
In its orbital architecture around Kepler-16, Kepler-16 b completes one full revolution every 228.776 Earth days at a semi-major axis of 0.7048 AU (situated at an orbital separation between Mercury's 0.39 AU and Venus's 0.72 AU). Its mean orbital velocity is approximately 33.5 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.0069 (ranging from 0.6999 AU at periapsis to 0.7097 AU at apoapsis), the planet experiences minimal orbital distance variation.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 8.449 R⊕, Kepler-16 b exceeds the empirical ~1.8–2.2 R⊕ Fulton radius valley threshold, indicating a substantial hydrogen-helium or supercritical volatile envelope without a conventional solid terrestrial surface.
The host star Kepler-16 is classified as a stellar host with an effective photospheric temperature of 4,450 K, a radius of 0.6489 R☉, a mass of 0.6897 M☉, an estimated bolometric luminosity of 0.148 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.8 Gyr and a metallicity of [Fe/H] = -0.3 dex (metal-poor relative to the Sun). From Earth, Kepler-16 shines at apparent V-band magnitude 12.144 (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-16 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 4,450 K |
| Stellar Radius | 0.6489 R☉ |
| Stellar Mass | 0.6897 M☉ |
| Bolometric Luminosity | 0.148 L☉ |
| Metallicity [Fe/H] | -0.300 dex |
| Stellar Age | 3.800 Gyr |
| Apparent Magnitude | V: 12.144 · G: 11.747 |
| System Architecture | 2 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.704800 AU |
| Orbital Period | 228.776 days |
| Mean Orbital Velocity | 33.5 km/s |
| Orbital Eccentricity (e) | 0.00690 |
| Orbital Inclination (i) | 90.0322° |
| Mean Bulk Density | 0.97 g/cm³ (39.6 km/s vesc) |
| Insolation Flux | 0.2517 S⊕ (~343 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 244.900 LY (75.085 pc) |