Kepler-1249 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1249 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-1249, located approximately 6211.8 light-years (1904.54 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0291% across the stellar disk), this world measures 2.38 Earth radii and has a measured mass of 6.26 Earth masses. Combining its mass and radius yields a mean bulk density of 2.56 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.11 g⊕ (10.89 m/s²), and an escape velocity of 18.1 km/s.

In its orbital architecture around Kepler-1249, Kepler-1249 b completes one full revolution every 24.335 Earth days at a semi-major axis of 0.167 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 74.7 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 647 K (+374°C / +705°F) and receiving 98.34 S⊕ (~133,835 W/m²), Kepler-1249 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1249 is classified as a stellar host with an effective photospheric temperature of 6,202 K, a radius of 1.28 R☉, a mass of 1.19 M☉, an estimated bolometric luminosity of 2.175 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.82 Gyr and a metallicity of [Fe/H] = 0.06 dex (metal-rich relative to the Sun). From Earth, Kepler-1249 shines at apparent V-band magnitude 15.391 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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