Kepler-508 b

Astrophysical Synthesis & Habitability Characterization

Kepler-508 b is a confirmed super-earth exoplanet orbiting the star Kepler-508, located approximately 1058.8 light-years (324.62 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0145% across the stellar disk), this world measures 1.64 Earth radii and has a measured mass of 3.33 Earth masses. Combining its mass and radius yields a mean bulk density of 4.16 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.24 g⊕ (12.16 m/s²), and an escape velocity of 15.9 km/s.

In its orbital architecture around Kepler-508, Kepler-508 b completes one full revolution every 25.309 Earth days at a semi-major axis of 0.17274 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 74.3 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 710 K (+437°C / +819°F) and receiving 60.37 S⊕ (~82,166 W/m²), Kepler-508 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-508 is classified as a stellar host with an effective photospheric temperature of 6,025 K, a radius of 1.25 R☉, a mass of 1.16 M☉, an estimated bolometric luminosity of 1.847 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.55 Gyr and a metallicity of [Fe/H] = 0.18 dex (metal-rich relative to the Sun). From Earth, Kepler-508 shines at apparent V-band magnitude 11.592 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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