Kepler-1647 b
Astrophysical Synthesis & Habitability Characterization
Kepler-1647 b is a confirmed gas giant exoplanet orbiting the star Kepler-1647, located approximately 3954.5 light-years (1212.45 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.3697% across the stellar disk), this world measures 11.874 Earth radii (1.06 Jupiter radii) and has a measured mass of 483 Earth masses (1.52 Jupiter masses). Combining its mass and radius yields a mean bulk density of 1.59 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 3.43 g⊕ (33.64 m/s²), and an escape velocity of 71.3 km/s.
In its orbital architecture around Kepler-1647, Kepler-1647 b completes one full revolution every 1107.592 Earth days (3.03Julian years) at a semi-major axis of 2.7205 AU (corresponding to the middle-system regime between Mars at 1.52 AU and Jupiter at 5.20 AU). Its mean orbital velocity is approximately 26.7 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.0581 carries the world between 2.5624 AU at periapsis and 2.8786 AU at apoapsis, driving measurable seasonal insolation cycles.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 11.874 R⊕, Kepler-1647 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-1647 is classified as a stellar host with an effective photospheric temperature of 6,210 K, a radius of 1.7903 R☉, a mass of 1.2207 M☉, an estimated bolometric luminosity of 4.277 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.4 Gyr and a metallicity of [Fe/H] = -0.14 dex (metal-poor relative to the Sun). From Earth, Kepler-1647 shines at apparent V-band magnitude 13.668 (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-1647 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,210 K |
| Stellar Radius | 1.7903 R☉ |
| Stellar Mass | 1.2207 M☉ |
| Bolometric Luminosity | 4.277 L☉ |
| Metallicity [Fe/H] | -0.140 dex |
| Stellar Age | 4.400 Gyr |
| Apparent Magnitude | V: 13.668 · G: 13.579 |
| System Architecture | 2 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 2.720500 AU |
| Orbital Period | 1107.592 days |
| Mean Orbital Velocity | 26.7 km/s |
| Orbital Eccentricity (e) | 0.05810 |
| Orbital Inclination (i) | 90.0972° |
| Mean Bulk Density | 1.59 g/cm³ (71.3 km/s vesc) |
| Insolation Flux | 0.5956 S⊕ (~811 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 3954.500 LY (1212.450 pc) |