Kepler-1253 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1253 b is a confirmed super-earth exoplanet orbiting the star Kepler-1253, located approximately 1678.2 light-years (514.52 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0123% across the stellar disk), this world measures 1.33 Earth radii and has a measured mass of 2.33 Earth masses. Combining its mass and radius yields a mean bulk density of 5.46 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.32 g⊕ (12.94 m/s²), and an escape velocity of 14.8 km/s.

In its orbital architecture around Kepler-1253, Kepler-1253 b completes one full revolution every 68.886 Earth days at a semi-major axis of 0.31444 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 49.7 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 501 K (+228°C / +442°F) and receiving 21.62 S⊕ (~29,430 W/m²), Kepler-1253 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1253 is classified as a stellar host with an effective photospheric temperature of 5,850 K, a radius of 1.1 R☉, a mass of 0.97 M☉, an estimated bolometric luminosity of 1.271 L☉. Stellar evolution modeling indicates an estimated stellar age of 7.08 Gyr and a metallicity of [Fe/H] = -0.14 dex (metal-poor relative to the Sun). From Earth, Kepler-1253 shines at apparent V-band magnitude 12.588 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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