Kepler-1799 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1799 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-1799, located approximately 7353.8 light-years (2254.69 parsecs) from the Solar System. First announced in 2021 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.1689% across the stellar disk), this world measures 4.128 Earth radii (0.37 Jupiter radii) and has a measured mass of 15.9 Earth masses. Combining its mass and radius yields a mean bulk density of 1.25 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.93 g⊕ (9.12 m/s²), and an escape velocity of 22 km/s.

In its orbital architecture around Kepler-1799, Kepler-1799 b completes one full revolution every 11.93 Earth days at a semi-major axis of 0.1028 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 93.7 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 770 K (+497°C / +927°F) and receiving 83.04 S⊕ (~113,017 W/m²), Kepler-1799 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1799 is classified as a stellar host with an effective photospheric temperature of 5,831 K, a radius of 0.921 R☉, a mass of 1.016 M☉, an estimated bolometric luminosity of 0.88 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.5 Gyr and a metallicity of [Fe/H] = 0 dex (near-solar heavy-element abundance). From Earth, Kepler-1799 shines at apparent V-band magnitude 15.99 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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