Kepler-1768 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1768 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-1768, located approximately 2063.8 light-years (632.77 parsecs) from the Solar System. First announced in 2021 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.017% across the stellar disk), this world measures 2.233 Earth radii and has a measured mass of 5.62 Earth masses. Combining its mass and radius yields a mean bulk density of 2.78 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.13 g⊕ (11.08 m/s²), and an escape velocity of 17.7 km/s.

In its orbital architecture around Kepler-1768, Kepler-1768 b completes one full revolution every 15.136 Earth days at a semi-major axis of 0.1286 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 92.4 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 933 K (+660°C / +1220°F) and receiving 179.16 S⊕ (~243,837 W/m²), Kepler-1768 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1768 is classified as a stellar host with an effective photospheric temperature of 6,050 K, a radius of 1.572 R☉, a mass of 1.24 M☉, an estimated bolometric luminosity of 2.97 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = 0.14 dex (metal-rich relative to the Sun). From Earth, Kepler-1768 shines at apparent V-band magnitude 13.565 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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