Kepler-1645 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1645 b is a confirmed super-earth exoplanet orbiting the star Kepler-1645, located approximately 3921.9 light-years (1202.47 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0256% across the stellar disk), this world measures 1.78 Earth radii and has a measured mass of 3.82 Earth masses. Combining its mass and radius yields a mean bulk density of 3.73 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.21 g⊕ (11.87 m/s²), and an escape velocity of 16.4 km/s.

In its orbital architecture around Kepler-1645, Kepler-1645 b completes one full revolution every 16.178 Earth days at a semi-major axis of 0.1285 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 86.4 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 754 K (+481°C / +898°F) and receiving 138.54 S⊕ (~188,550 W/m²), Kepler-1645 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1645 is classified as a stellar host with an effective photospheric temperature of 5,812 K, a radius of 1.02 R☉, a mass of 1.02 M☉, an estimated bolometric luminosity of 1.065 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.17 Gyr and a metallicity of [Fe/H] = 0.04 dex (near-solar heavy-element abundance). From Earth, Kepler-1645 shines at apparent V-band magnitude 14.566 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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