Kepler-771 b

Astrophysical Synthesis & Habitability Characterization

Kepler-771 b is a confirmed super-earth exoplanet orbiting the star Kepler-771, located approximately 4546.1 light-years (1393.85 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0253% across the stellar disk), this world measures 1.82 Earth radii and has a measured mass of 3.97 Earth masses. Combining its mass and radius yields a mean bulk density of 3.63 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.2 g⊕ (11.77 m/s²), and an escape velocity of 16.5 km/s.

In its orbital architecture around Kepler-771, Kepler-771 b completes one full revolution every 8.735 Earth days at a semi-major axis of 0.0843 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 105 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 890 K (+617°C / +1143°F) and receiving 339.30 S⊕ (~461,782 W/m²), Kepler-771 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-771 is classified as a stellar host with an effective photospheric temperature of 5,906 K, a radius of 1.05 R☉, a mass of 1.03 M☉, an estimated bolometric luminosity of 1.203 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.72 Gyr and a metallicity of [Fe/H] = 0.01 dex (near-solar heavy-element abundance). From Earth, Kepler-771 shines at apparent V-band magnitude 14.958 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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