Kepler-1845 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1845 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-1845, located approximately 2318.1 light-years (710.72 parsecs) from the Solar System. First announced in 2021 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.1017% across the stellar disk), this world measures 2.438 Earth radii and has a measured mass of 6.52 Earth masses. Combining its mass and radius yields a mean bulk density of 2.48 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.1 g⊕ (10.79 m/s²), and an escape velocity of 18.3 km/s.

In its orbital architecture around Kepler-1845, Kepler-1845 b completes one full revolution every 11.607 Earth days at a semi-major axis of 0.0885 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 83 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 584 K (+311°C / +592°F) and receiving 27.47 S⊕ (~37,387 W/m²), Kepler-1845 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1845 is classified as a stellar host with an effective photospheric temperature of 4,703 K, a radius of 0.701 R☉, a mass of 0.686 M☉, an estimated bolometric luminosity of 0.216 L☉. Stellar evolution modeling indicates an estimated stellar age of 1 Gyr and a metallicity of [Fe/H] = -0.14 dex (metal-poor relative to the Sun). From Earth, Kepler-1845 shines at apparent V-band magnitude 16.117 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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