Kepler-1796 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1796 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-1796, located approximately 2693.7 light-years (825.88 parsecs) from the Solar System. First announced in 2021 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0706% across the stellar disk), this world measures 2.75 Earth radii and has a measured mass of 8 Earth masses. Combining its mass and radius yields a mean bulk density of 2.12 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.06 g⊕ (10.4 m/s²), and an escape velocity of 19.1 km/s.

In its orbital architecture around Kepler-1796, Kepler-1796 b completes one full revolution every 29.456 Earth days at a semi-major axis of 0.1879 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 69.4 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 598 K (+325°C / +617°F) and receiving 30.30 S⊕ (~41,238 W/m²), Kepler-1796 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1796 is classified as a stellar host with an effective photospheric temperature of 6,036 K, a radius of 0.949 R☉, a mass of 1.018 M☉, an estimated bolometric luminosity of 1.073 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.4 Gyr and a metallicity of [Fe/H] = -0.16 dex (metal-poor relative to the Sun). From Earth, Kepler-1796 shines at apparent V-band magnitude 14.493 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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