Kepler-1867 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1867 b is a confirmed terrestrial exoplanet orbiting the star Kepler-1867, located approximately 2219.8 light-years (680.58 parsecs) from the Solar System. First announced in 2021 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.017% across the stellar disk), this world measures 1.16 Earth radii and has a measured mass of 1.65 Earth masses. Combining its mass and radius yields a mean bulk density of 5.83 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.23 g⊕ (12.06 m/s²), and an escape velocity of 13.3 km/s.

In its orbital architecture around Kepler-1867, Kepler-1867 b completes one full revolution every 9.887 Earth days at a semi-major axis of 0.0872 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 95.9 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 768 K (+495°C / +923°F) and receiving 82.32 S⊕ (~112,038 W/m²), Kepler-1867 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1867 is classified as a stellar host with an effective photospheric temperature of 5,693 K, a radius of 0.816 R☉, a mass of 0.911 M☉, an estimated bolometric luminosity of 0.628 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.5 Gyr and a metallicity of [Fe/H] = -0.24 dex (metal-poor relative to the Sun). From Earth, Kepler-1867 shines at apparent V-band magnitude 13.549 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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