Kepler-1158 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1158 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-1158, located approximately 4841 light-years (1484.25 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0121% across the stellar disk), this world measures 2.34 Earth radii and has a measured mass of 6.08 Earth masses. Combining its mass and radius yields a mean bulk density of 2.62 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 km/s.

In its orbital architecture around Kepler-1158, Kepler-1158 b completes one full revolution every 13.54 Earth days at a semi-major axis of 0.12643 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 101.6 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 1079 K (+806°C / +1483°F) and receiving 449.70 S⊕ (~612,040 W/m²), Kepler-1158 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1158 is classified as a stellar host with an effective photospheric temperature of 6,203 K, a radius of 1.95 R☉, a mass of 1.41 M☉, an estimated bolometric luminosity of 5.051 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.88 Gyr and a metallicity of [Fe/H] = 0.18 dex (metal-rich relative to the Sun). From Earth, Kepler-1158 shines at apparent V-band magnitude 13.618 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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