Kepler-1686 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1686 b is a confirmed super-earth exoplanet orbiting the star Kepler-1686, located approximately 2380.4 light-years (729.82 parsecs) from the Solar System. First announced in 2020 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0119% across the stellar disk), this world measures 1.426 Earth radii and has a measured mass of 2.62 Earth masses. Combining its mass and radius yields a mean bulk density of 4.98 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.29 g⊕ (12.65 m/s²), and an escape velocity of 15.2 km/s.

In its orbital architecture around Kepler-1686, Kepler-1686 b completes one full revolution every 9.31 Earth days at a semi-major axis of 0.08827 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 103.1 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 913 K (+640°C / +1184°F) and receiving 167.20 S⊕ (~227,559 W/m²), Kepler-1686 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1686 is classified as a stellar host with an effective photospheric temperature of 5,715 K, a radius of 1.1995 R☉, a mass of 1.02 M☉, an estimated bolometric luminosity of 1.377 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.37 Gyr and a metallicity of [Fe/H] = 0.078 dex (metal-rich relative to the Sun). From Earth, Kepler-1686 shines at apparent V-band magnitude 13.661 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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