Kepler-1186 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1186 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-1186, located approximately 4361.5 light-years (1337.25 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0483% across the stellar disk), this world measures 2.23 Earth radii and has a measured mass of 5.6 Earth masses. Combining its mass and radius yields a mean bulk density of 2.78 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.13 g⊕ (11.08 m/s²), and an escape velocity of 17.7 km/s.

In its orbital architecture around Kepler-1186, Kepler-1186 b completes one full revolution every 16.077 Earth days at a semi-major axis of 0.1281 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 86.7 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 724 K (+451°C / +844°F) and receiving 85.39 S⊕ (~116,209 W/m²), Kepler-1186 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1186 is classified as a stellar host with an effective photospheric temperature of 5,635 K, a radius of 0.93 R☉, a mass of 0.95 M☉, an estimated bolometric luminosity of 0.782 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.47 Gyr and a metallicity of [Fe/H] = 0 dex (near-solar heavy-element abundance). From Earth, Kepler-1186 shines at apparent V-band magnitude 15.367 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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