Kepler-1303 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1303 b is a confirmed super-earth exoplanet orbiting the star Kepler-1303, located approximately 2928.2 light-years (897.78 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0169% across the stellar disk), this world measures 1.42 Earth radii and has a measured mass of 2.6 Earth masses. Combining its mass and radius yields a mean bulk density of 5.01 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.29 g⊕ (12.65 m/s²), and an escape velocity of 15.1 km/s.

In its orbital architecture around Kepler-1303, Kepler-1303 b completes one full revolution every 7.561 Earth days at a semi-major axis of 0.0751 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 108.1 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 891 K (+618°C / +1144°F) and receiving 182.38 S⊕ (~248,212 W/m²), Kepler-1303 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1303 is classified as a stellar host with an effective photospheric temperature of 5,771 K, a radius of 1 R☉, a mass of 1.01 M☉, an estimated bolometric luminosity of 0.995 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.47 Gyr and a metallicity of [Fe/H] = 0.04 dex (near-solar heavy-element abundance). From Earth, Kepler-1303 shines at apparent V-band magnitude 14.854 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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