Kepler-7 b

Astrophysical Synthesis & Habitability Characterization

Kepler-7 b is a confirmed gas giant exoplanet orbiting the star Kepler-7, located approximately 3009 light-years (922.56 parsecs) from the Solar System. First announced in 2009 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.7188% across the stellar disk), this world measures 18.181 Earth radii (1.62 Jupiter radii) and has a measured mass of 140.163 Earth masses (0.44 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.13 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.42 g⊕ (4.12 m/s²), and an escape velocity of 31.1 km/s.

In its orbital architecture around Kepler-7, Kepler-7 b completes one full revolution every 4.885 Earth days at a semi-major axis of 0.06067 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 135.1 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.

⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1630 K (+1357°C / +2475°F) and receiving 1,375.11 S⊕ (~1,871,525 W/m²), Kepler-7 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-7 is classified as a stellar host with an effective photospheric temperature of 5,933 K, a radius of 1.966 R☉, a mass of 1.359 M☉, an estimated bolometric luminosity of 4.297 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.9 Gyr and a metallicity of [Fe/H] = 0.11 dex (metal-rich relative to the Sun). From Earth, Kepler-7 shines at apparent V-band magnitude 13.008 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

Discovery Facility: Kepler · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).