Kepler-919 b

Astrophysical Synthesis & Habitability Characterization

Kepler-919 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-919, located approximately 3652.5 light-years (1119.87 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0291% across the stellar disk), this world measures 2.25 Earth radii and has a measured mass of 5.69 Earth masses. Combining its mass and radius yields a mean bulk density of 2.75 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.12 g⊕ (10.98 m/s²), and an escape velocity of 17.8 km/s.

In its orbital architecture around Kepler-919, Kepler-919 b completes one full revolution every 11.046 Earth days at a semi-major axis of 0.0981 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 96.6 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 869 K (+596°C / +1105°F) and receiving 153.92 S⊕ (~209,478 W/m²), Kepler-919 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-919 is classified as a stellar host with an effective photospheric temperature of 6,113 K, a radius of 1.21 R☉, a mass of 1.15 M☉, an estimated bolometric luminosity of 1.834 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.02 Gyr and a metallicity of [Fe/H] = 0.07 dex (metal-rich relative to the Sun). From Earth, Kepler-919 shines at apparent V-band magnitude 14.806 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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