Kepler-1670 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1670 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-1670, located approximately 6738.3 light-years (2065.98 parsecs) from the Solar System. First announced in 2020 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.041% across the stellar disk), this world measures 3.356 Earth radii (0.3 Jupiter radii) and has a measured mass of 11.2 Earth masses. Combining its mass and radius yields a mean bulk density of 1.63 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.99 g⊕ (9.71 m/s²), and an escape velocity of 20.4 km/s.

In its orbital architecture around Kepler-1670, Kepler-1670 b completes one full revolution every 20.5 Earth days at a semi-major axis of 0.1528 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 81.1 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 731 K (+458°C / +856°F) and receiving 67.67 S⊕ (~92,099 W/m²), Kepler-1670 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1670 is classified as a stellar host with an effective photospheric temperature of 5,838 K, a radius of 1.5189 R☉, a mass of 1.05 M☉, an estimated bolometric luminosity of 2.404 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.3 Gyr and a metallicity of [Fe/H] = -0.08 dex (near-solar heavy-element abundance). From Earth, Kepler-1670 shines at apparent V-band magnitude 15.743 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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