Kepler-422 b

Astrophysical Synthesis & Habitability Characterization

Kepler-422 b is a confirmed gas giant exoplanet orbiting the star Kepler-422, located approximately 2357.4 light-years (722.8 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.9082% across the stellar disk), this world measures 12.89 Earth radii (1.15 Jupiter radii) and has a measured mass of 136.66 Earth masses (0.43 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.35 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.82 g⊕ (8.04 m/s²), and an escape velocity of 36.4 km/s.

In its orbital architecture around Kepler-422, Kepler-422 b completes one full revolution every 7.891 Earth days at a semi-major axis of 0.082 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 113 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 1028 K (+755°C / +1391°F) and receiving 264.98 S⊕ (~360,642 W/m²), Kepler-422 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-422 is classified as a stellar host with an effective photospheric temperature of 5,972 K, a radius of 1.24 R☉, a mass of 1.15 M☉, an estimated bolometric luminosity of 1.755 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.4 Gyr and a metallicity of [Fe/H] = 0.23 dex (metal-rich relative to the Sun). From Earth, Kepler-422 shines at apparent V-band magnitude 13.524 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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