Kepler-1847 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1847 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-1847, located approximately 5524.6 light-years (1693.86 parsecs) from the Solar System. First announced in 2021 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0682% across the stellar disk), this world measures 2.745 Earth radii and has a measured mass of 7.97 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-1847, Kepler-1847 b completes one full revolution every 11.13 Earth days at a semi-major axis of 0.0989 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 96.7 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 843 K (+570°C / +1058°F) and receiving 119.44 S⊕ (~162,558 W/m²), Kepler-1847 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1847 is classified as a stellar host with an effective photospheric temperature of 6,122 K, a radius of 0.964 R☉, a mass of 1.041 M☉, an estimated bolometric luminosity of 1.171 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.4 Gyr and a metallicity of [Fe/H] = -0.18 dex (metal-poor relative to the Sun). From Earth, Kepler-1847 shines at apparent V-band magnitude 16.027 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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