Kepler-734 b

Astrophysical Synthesis & Habitability Characterization

Kepler-734 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-734, located approximately 3774.3 light-years (1157.21 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.1751% across the stellar disk), this world measures 3.56 Earth radii (0.32 Jupiter radii) and has a measured mass of 12.4 Earth masses. Combining its mass and radius yields a mean bulk density of 1.52 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.98 g⊕ (9.61 m/s²), and an escape velocity of 20.9 km/s.

In its orbital architecture around Kepler-734, Kepler-734 b completes one full revolution every 6.105 Earth days at a semi-major axis of 0.0583 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 103.9 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 784 K (+511°C / +952°F) and receiving 89.25 S⊕ (~121,469 W/m²), Kepler-734 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-734 is classified as a stellar host with an effective photospheric temperature of 5,326 K, a radius of 0.78 R☉, a mass of 0.85 M☉, an estimated bolometric luminosity of 0.439 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.34 Gyr and a metallicity of [Fe/H] = -0.17 dex (metal-poor relative to the Sun). From Earth, Kepler-734 shines at apparent V-band magnitude 14.469 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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