Kepler-836 b

Astrophysical Synthesis & Habitability Characterization

Kepler-836 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-836, located approximately 3196.4 light-years (980.04 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0579% across the stellar disk), this world measures 2.73 Earth radii and has a measured mass of 7.9 Earth masses. Combining its mass and radius yields a mean bulk density of 2.14 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.06 g⊕ (10.4 m/s²), and an escape velocity of 19 km/s.

In its orbital architecture around Kepler-836, Kepler-836 b completes one full revolution every 11.361 Earth days at a semi-major axis of 0.1013 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 97 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 135.80 S⊕ (~184,820 W/m²), Kepler-836 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-836 is classified as a stellar host with an effective photospheric temperature of 5,895 K, a radius of 1.04 R☉, a mass of 1.03 M☉, an estimated bolometric luminosity of 1.172 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.27 Gyr and a metallicity of [Fe/H] = -0.01 dex (near-solar heavy-element abundance). From Earth, Kepler-836 shines at apparent V-band magnitude 14.672 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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