Kepler-596 b

Astrophysical Synthesis & Habitability Characterization

Kepler-596 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-596, located approximately 3339.3 light-years (1023.85 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0577% across the stellar disk), this world measures 3.46 Earth radii (0.31 Jupiter radii) and has a measured mass of 11.8 Earth masses. Combining its mass and radius yields a mean bulk density of 1.57 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.99 g⊕ (9.71 m/s²), and an escape velocity of 20.7 km/s.

In its orbital architecture around Kepler-596, Kepler-596 b completes one full revolution every 21.3 Earth days at a semi-major axis of 0.15161 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 77.4 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 725 K (+452°C / +846°F) and receiving 82.30 S⊕ (~112,013 W/m²), Kepler-596 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-596 is classified as a stellar host with an effective photospheric temperature of 6,267 K, a radius of 1.32 R☉, a mass of 1.21 M☉, an estimated bolometric luminosity of 2.411 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.69 Gyr and a metallicity of [Fe/H] = 0.03 dex (near-solar heavy-element abundance). From Earth, Kepler-596 shines at apparent V-band magnitude 14.128 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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