Kepler-703 b

Astrophysical Synthesis & Habitability Characterization

Kepler-703 b is a confirmed gas giant exoplanet orbiting the star Kepler-703, located approximately 3773.1 light-years (1156.83 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.3504% across the stellar disk), this world measures 8.2 Earth radii (0.73 Jupiter radii) and has a measured mass of 51.1 Earth masses (0.16 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.51 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.76 g⊕ (7.45 m/s²), and an escape velocity of 27.9 km/s.

In its orbital architecture around Kepler-703, Kepler-703 b completes one full revolution every 4.584 Earth days at a semi-major axis of 0.0535 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 127 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 1038 K (+765°C / +1409°F) and receiving 373.11 S⊕ (~507,800 W/m²), Kepler-703 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-703 is classified as a stellar host with an effective photospheric temperature of 6,185 K, a radius of 1.27 R☉, a mass of 1.18 M☉, an estimated bolometric luminosity of 2.118 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.69 Gyr and a metallicity of [Fe/H] = 0.05 dex (near-solar heavy-element abundance). From Earth, Kepler-703 shines at apparent V-band magnitude 15.599 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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