Kepler-626 b

Astrophysical Synthesis & Habitability Characterization

Kepler-626 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-626, located approximately 2073.2 light-years (635.64 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.04% across the stellar disk), this world measures 2.29 Earth radii and has a measured mass of 5.86 Earth masses. Combining its mass and radius yields a mean bulk density of 2.69 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.12 g⊕ (10.98 m/s²), and an escape velocity of 17.9 km/s.

In its orbital architecture around Kepler-626, Kepler-626 b completes one full revolution every 14.486 Earth days at a semi-major axis of 0.10913 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 82 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 784 K (+511°C / +952°F) and receiving 69.80 S⊕ (~94,991 W/m²), Kepler-626 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-626 is classified as a stellar host with an effective photospheric temperature of 5,813 K, a radius of 1.05 R☉, a mass of 1.01 M☉, an estimated bolometric luminosity of 1.129 L☉. Stellar evolution modeling indicates an estimated stellar age of 5.37 Gyr and a metallicity of [Fe/H] = 0.01 dex (near-solar heavy-element abundance). From Earth, Kepler-626 shines at apparent V-band magnitude 14.086 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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