Kepler-1625 b
Astrophysical Synthesis & Habitability Characterization
Kepler-1625 b is a confirmed gas giant exoplanet orbiting the star Kepler-1625, located approximately 7534.6 light-years (2310.11 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.3493% across the stellar disk), this world measures 6.06 Earth radii (0.54 Jupiter radii) and has a measured mass of 30.6 Earth masses (0.1 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.76 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.83 g⊕ (8.14 m/s²), and an escape velocity of 25.1 km/s.
In its orbital architecture around Kepler-1625, Kepler-1625 b completes one full revolution every 287.379 Earth days at a semi-major axis of 0.87762 AU (comparable to the inner terrestrial zone between Venus, Earth at 1.00 AU, and Mars at 1.52 AU). Its mean orbital velocity is approximately 33.2 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.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 6.060 R⊕, Kepler-1625 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-1625 is classified as a stellar host with an effective photospheric temperature of 5,677 K, a radius of 0.94 R☉, a mass of 0.96 M☉, an estimated bolometric luminosity of 0.823 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.37 Gyr and a metallicity of [Fe/H] = 0.01 dex (near-solar heavy-element abundance). From Earth, Kepler-1625 shines at apparent V-band magnitude 16.227 (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-1625 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,677 K |
| Stellar Radius | 0.9400 R☉ |
| Stellar Mass | 0.9600 M☉ |
| Bolometric Luminosity | 0.823 L☉ |
| Metallicity [Fe/H] | 0.010 dex |
| Stellar Age | 4.370 Gyr |
| Apparent Magnitude | V: 16.227 · G: 15.763 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.877620 AU |
| Orbital Period | 287.379 days |
| Mean Orbital Velocity | 33.2 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.9900° |
| Mean Bulk Density | 0.76 g/cm³ (25.1 km/s vesc) |
| Insolation Flux | 3.3000 S⊕ (~4,491 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 7534.600 LY (2310.110 pc) |