Kepler-1175 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1175 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-1175, located approximately 3659.1 light-years (1121.89 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.1016% across the stellar disk), this world measures 2.99 Earth radii and has a measured mass of 9.22 Earth masses. Combining its mass and radius yields a mean bulk density of 1.9 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.03 g⊕ (10.1 m/s²), and an escape velocity of 19.6 km/s.

In its orbital architecture around Kepler-1175, Kepler-1175 b completes one full revolution every 37.946 Earth days at a semi-major axis of 0.2181 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 62.5 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 515 K (+242°C / +468°F) and receiving 12.94 S⊕ (~17,609 W/m²), Kepler-1175 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1175 is classified as a stellar host with an effective photospheric temperature of 5,453 K, a radius of 0.86 R☉, a mass of 0.9 M☉, an estimated bolometric luminosity of 0.587 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.17 Gyr and a metallicity of [Fe/H] = -0.04 dex (near-solar heavy-element abundance). From Earth, Kepler-1175 shines at apparent V-band magnitude 15.972 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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