KOI-351 h
Astrophysical Synthesis & Habitability Characterization
KOI-351 h is a confirmed gas giant exoplanet orbiting the star KOI-351, located approximately 2766.6 light-years (848.25 parsecs) from the Solar System. First announced in 2013 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.7578% across the stellar disk), this world measures 11.252 Earth radii (1 Jupiter radii) and has a measured mass of 203 Earth masses (0.64 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.79 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.6 g⊕ (15.69 m/s²), and an escape velocity of 47.5 km/s.
In its orbital architecture around KOI-351, KOI-351 h completes one full revolution every 331.603 Earth days at a semi-major axis of 0.97062 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 31.8 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.0276 (ranging from 0.9438 AU at periapsis to 0.9974 AU at apoapsis), the planet experiences minimal orbital distance variation.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 11.252 R⊕, KOI-351 h 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 KOI-351 is classified as a stellar host with an effective photospheric temperature of 6,031 K, a radius of 1.185 R☉, a mass of 1.242 M☉, an estimated bolometric luminosity of 1.667 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.53 Gyr and a metallicity of [Fe/H] = 0.083 dex (metal-rich relative to the Sun). From Earth, KOI-351 shines at apparent V-band magnitude 13.883 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The KOI-351 system is a multi-planet architecture hosting 8 confirmed worlds, with KOI-351 h sharing its stellar neighborhood alongside KOI-351 b, KOI-351 c, Kepler-90 i, KOI-351 d, KOI-351 e, KOI-351 f, KOI-351 g.
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 | KOI-351 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,031 K |
| Stellar Radius | 1.1850 R☉ |
| Stellar Mass | 1.2420 M☉ |
| Bolometric Luminosity | 1.667 L☉ |
| Metallicity [Fe/H] | 0.083 dex |
| Stellar Age | 0.530 Gyr |
| Apparent Magnitude | V: 13.883 · G: 13.740 |
| System Architecture | 1 Star, 8 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.970620 AU |
| Orbital Period | 331.603 days |
| Mean Orbital Velocity | 31.8 km/s |
| Orbital Eccentricity (e) | 0.02760 |
| Orbital Inclination (i) | 89.9270° |
| Mean Bulk Density | 0.79 g/cm³ (47.5 km/s vesc) |
| Insolation Flux | 1.8490 S⊕ (~2,516 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2766.600 LY (848.254 pc) |