Kepler-1634 b
Astrophysical Synthesis & Habitability Characterization
Kepler-1634 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-1634, located approximately 2013.5 light-years (617.34 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.108% across the stellar disk), this world measures 3.19 Earth radii (0.28 Jupiter radii) and has a measured mass of 10.3 Earth masses. Combining its mass and radius yields a mean bulk density of 1.75 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.01 g⊕ (9.9 m/s²), and an escape velocity of 20.1 km/s.
In its orbital architecture around Kepler-1634, Kepler-1634 b completes one full revolution every 374.876 Earth days (1.03Julian years) at a semi-major axis of 1.0525 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 30.5 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 3.190 R⊕, Kepler-1634 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-1634 is classified as a stellar host with an effective photospheric temperature of 5,474 K, a radius of 0.89 R☉, a mass of 0.92 M☉, an estimated bolometric luminosity of 0.638 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.47 Gyr and a metallicity of [Fe/H] = 0.02 dex (near-solar heavy-element abundance). From Earth, Kepler-1634 shines at apparent V-band magnitude 14.636 (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-1634 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,474 K |
| Stellar Radius | 0.8900 R☉ |
| Stellar Mass | 0.9200 M☉ |
| Bolometric Luminosity | 0.638 L☉ |
| Metallicity [Fe/H] | 0.020 dex |
| Stellar Age | 4.470 Gyr |
| Apparent Magnitude | V: 14.636 · G: 14.486 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 1.052500 AU |
| Orbital Period | 374.876 days |
| Mean Orbital Velocity | 30.5 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.8400° |
| Mean Bulk Density | 1.75 g/cm³ (20.1 km/s vesc) |
| Insolation Flux | 0.5440 S⊕ (~740 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2013.500 LY (617.339 pc) |