Kepler-1337 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1337 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-1337, located approximately 1962.2 light-years (601.63 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.1087% across the stellar disk), this world measures 2.41 Earth radii and has a measured mass of 6.39 Earth masses. Combining its mass and radius yields a mean bulk density of 2.52 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.1 g⊕ (10.79 m/s²), and an escape velocity of 18.2 km/s.

In its orbital architecture around Kepler-1337, Kepler-1337 b completes one full revolution every 24.4 Earth days at a semi-major axis of 0.1441 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 64.2 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 437 K (+164°C / +327°F) and receiving 9.18 S⊕ (~12,498 W/m²), Kepler-1337 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1337 is classified as a stellar host with an effective photospheric temperature of 4,523 K, a radius of 0.67 R☉, a mass of 0.7 M☉, an estimated bolometric luminosity of 0.169 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.27 Gyr and a metallicity of [Fe/H] = -0.09 dex (near-solar heavy-element abundance). From Earth, Kepler-1337 shines at apparent V-band magnitude 16.21 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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