Kepler-909 b

Astrophysical Synthesis & Habitability Characterization

Kepler-909 b is a confirmed super-earth exoplanet orbiting the star Kepler-909, located approximately 1009.8 light-years (309.6 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.012% across the stellar disk), this world measures 1.47 Earth radii and has a measured mass of 2.76 Earth masses. Combining its mass and radius yields a mean bulk density of 4.79 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.28 g⊕ (12.55 m/s²), and an escape velocity of 15.3 km/s.

In its orbital architecture around Kepler-909, Kepler-909 b completes one full revolution every 13.933 Earth days at a semi-major axis of 0.11873 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 92.7 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 852 K (+579°C / +1074°F) and receiving 127.24 S⊕ (~173,174 W/m²), Kepler-909 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-909 is classified as a stellar host with an effective photospheric temperature of 6,154 K, a radius of 1.23 R☉, a mass of 1.17 M☉, an estimated bolometric luminosity of 1.947 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.88 Gyr and a metallicity of [Fe/H] = 0.08 dex (metal-rich relative to the Sun). From Earth, Kepler-909 shines at apparent V-band magnitude 11.626 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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