Kepler-1644 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1644 b is a confirmed super-earth exoplanet orbiting the star Kepler-1644, located approximately 2052.4 light-years (629.27 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0402% across the stellar disk), this world measures 1.88 Earth radii and has a measured mass of 4.19 Earth masses. Combining its mass and radius yields a mean bulk density of 3.48 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.19 g⊕ (11.67 m/s²), and an escape velocity of 16.7 km/s.

In its orbital architecture around Kepler-1644, Kepler-1644 b completes one full revolution every 21.091 Earth days at a semi-major axis of 0.142 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 73.2 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 606 K (+333°C / +631°F) and receiving 31.86 S⊕ (~43,361 W/m²), Kepler-1644 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1644 is classified as a stellar host with an effective photospheric temperature of 5,499 K, a radius of 0.86 R☉, a mass of 0.89 M☉, an estimated bolometric luminosity of 0.607 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.27 Gyr and a metallicity of [Fe/H] = -0.1 dex (near-solar heavy-element abundance). From Earth, Kepler-1644 shines at apparent V-band magnitude 14.397 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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