Kepler-302 c

Astrophysical Synthesis & Habitability Characterization

Kepler-302 c is a confirmed gas giant exoplanet orbiting the star Kepler-302, located approximately 4574.6 light-years (1402.58 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.8753% across the stellar disk), this world has a measured radius of 12.45 Earth radii (1.11 R♃), though radial-velocity mass constraints remain unmeasured in the current composite catalogue.

In its orbital architecture around Kepler-302, Kepler-302 c completes one full revolution every 127.282 Earth days at a semi-major axis of 0.503 AU (situated at an orbital separation between Mercury's 0.39 AU and Venus's 0.72 AU). Its mean orbital velocity is approximately 43 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 392 K (+119°C / +246°F) and receiving 4.59 S⊕ (~6,240 W/m²), Kepler-302 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-302 is classified as a stellar host with an effective photospheric temperature of 5,740 K, a radius of 1.22 R☉, a mass of 1.021 M☉, an estimated bolometric luminosity of 1.45 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.47 Gyr and a metallicity of [Fe/H] = 0.16 dex (metal-rich relative to the Sun). From Earth, Kepler-302 shines at apparent V-band magnitude 15.694 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-302 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-302 c sharing its stellar neighborhood alongside Kepler-302 b.

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