Kepler-1256 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1256 b is a confirmed super-earth exoplanet orbiting the star Kepler-1256, located approximately 2906.7 light-years (891.19 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0101% across the stellar disk), this world measures 1.49 Earth radii and has a measured mass of 2.83 Earth masses. Combining its mass and radius yields a mean bulk density of 4.72 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.27 g⊕ (12.45 m/s²), and an escape velocity of 15.4 km/s.

In its orbital architecture around Kepler-1256, Kepler-1256 b completes one full revolution every 12.413 Earth days at a semi-major axis of 0.10733 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 94.1 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 933 K (+660°C / +1220°F) and receiving 211.55 S⊕ (~287,918 W/m²), Kepler-1256 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1256 is classified as a stellar host with an effective photospheric temperature of 6,129 K, a radius of 1.36 R☉, a mass of 1.17 M☉, an estimated bolometric luminosity of 2.342 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.72 Gyr and a metallicity of [Fe/H] = 0.05 dex (near-solar heavy-element abundance). From Earth, Kepler-1256 shines at apparent V-band magnitude 13.685 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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