Kepler-1663 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1663 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-1663, located approximately 1102.2 light-years (337.93 parsecs) from the Solar System. First announced in 2020 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.2322% across the stellar disk), this world measures 3.304 Earth radii (0.29 Jupiter radii) and has a measured mass of 10.9 Earth masses. Combining its mass and radius yields a mean bulk density of 1.67 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1 g⊕ (9.81 m/s²), and an escape velocity of 20.3 km/s.

In its orbital architecture around Kepler-1663, Kepler-1663 b completes one full revolution every 17.605 Earth days at a semi-major axis of 0.1072 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 66.2 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 362 K (+89°C / +192°F) and receiving 4.07 S⊕ (~5,539 W/m²), Kepler-1663 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1663 is classified as a stellar host with an effective photospheric temperature of 3,844 K, a radius of 0.6286 R☉, a mass of 0.6108 M☉, an estimated bolometric luminosity of 0.077 L☉. Stellar evolution modeling indicates an estimated stellar age of 0 Gyr and a metallicity of [Fe/H] = 0.06 dex (metal-rich relative to the Sun). From Earth, Kepler-1663 shines at apparent V-band magnitude 16.069 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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