Kepler-5 b

Astrophysical Synthesis & Habitability Characterization

Kepler-5 b is a confirmed gas giant exoplanet orbiting the star Kepler-5, located approximately 2934.7 light-years (899.78 parsecs) from the Solar System. First announced in 2009 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.668% across the stellar disk), this world measures 15.984 Earth radii (1.43 Jupiter radii) and has a measured mass of 670.939 Earth masses (2.11 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.91 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 2.63 g⊕ (25.79 m/s²), and an escape velocity of 72.5 km/s.

In its orbital architecture around Kepler-5, Kepler-5 b completes one full revolution every 3.548 Earth days at a semi-major axis of 0.0538 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 164.9 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 1750 K (+1477°C / +2691°F) and receiving 1,822.76 S⊕ (~2,480,774 W/m²), Kepler-5 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-5 is classified as a stellar host with an effective photospheric temperature of 6,297 K, a radius of 1.793 R☉, a mass of 1.374 M☉, an estimated bolometric luminosity of 4.535 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.88 Gyr and a metallicity of [Fe/H] = 0.04 dex (near-solar heavy-element abundance). From Earth, Kepler-5 shines at apparent V-band magnitude 13.325 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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