Kepler-824 b

Astrophysical Synthesis & Habitability Characterization

Kepler-824 b is a confirmed super-earth exoplanet orbiting the star Kepler-824, located approximately 3918.4 light-years (1201.4 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0197% across the stellar disk), this world measures 1.87 Earth radii and has a measured mass of 4.16 Earth masses. Combining its mass and radius yields a mean bulk density of 3.51 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.19 g⊕ (11.67 m/s²), and an escape velocity of 16.7 km/s.

In its orbital architecture around Kepler-824, Kepler-824 b completes one full revolution every 4.514 Earth days at a semi-major axis of 0.055 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 132.5 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 1231 K (+958°C / +1756°F) and receiving 454.60 S⊕ (~618,716 W/m²), Kepler-824 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-824 is classified as a stellar host with an effective photospheric temperature of 6,035 K, a radius of 1.22 R☉, a mass of 1.15 M☉, an estimated bolometric luminosity of 1.771 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.31 Gyr and a metallicity of [Fe/H] = 0.14 dex (metal-rich relative to the Sun). From Earth, Kepler-824 shines at apparent V-band magnitude 15.051 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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