Kepler-1813 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1813 b is a confirmed super-earth exoplanet orbiting the star Kepler-1813. First announced in 2021 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0271% across the stellar disk), this world measures 1.413 Earth radii and has a measured mass of 2.58 Earth masses. Combining its mass and radius yields a mean bulk density of 5.04 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.29 g⊕ (12.65 m/s²), and an escape velocity of 15.1 km/s.

In its orbital architecture around Kepler-1813, Kepler-1813 b completes one full revolution every 2.818 Earth days at a semi-major axis of 0.0364 AU (an ultra-close orbit less than one-seventh of Mercury's 0.387 AU distance from the Sun, where strong stellar tidal forces typically induce synchronous rotation). Its mean orbital velocity is approximately 140.5 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 1059 K (+786°C / +1447°F) and receiving 298.20 S⊕ (~405,850 W/m²), Kepler-1813 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1813 is classified as a stellar host with an effective photospheric temperature of 5,167 K, a radius of 0.787 R☉, a mass of 0.812 M☉, an estimated bolometric luminosity of 0.396 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.3 Gyr and a metallicity of [Fe/H] = -0.04 dex (near-solar heavy-element abundance). From Earth, Kepler-1813 shines at apparent V-band magnitude 15.639 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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