Kepler-1927 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1927 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-1927, located approximately 3558.4 light-years (1091 parsecs) from the Solar System. First announced in 2021 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0158% across the stellar disk), this world measures 3.406 Earth radii (0.3 Jupiter radii) and has a measured mass of 11.5 Earth masses. Combining its mass and radius yields a mean bulk density of 1.6 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.99 g⊕ (9.71 m/s²), and an escape velocity of 20.6 km/s.

In its orbital architecture around Kepler-1927, Kepler-1927 b completes one full revolution every 73.75 Earth days at a semi-major axis of 0.38733 AU (situated at an orbital separation between Mercury's 0.39 AU and Venus's 0.72 AU). Its mean orbital velocity is approximately 57.1 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 677 K (+404°C / +759°F) and receiving 34.70 S⊕ (~47,227 W/m²), Kepler-1927 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1927 is classified as a stellar host with an effective photospheric temperature of 6,056 K, a radius of 2.481 R☉, a mass of 1.408 M☉, an estimated bolometric luminosity of 7.428 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.88 Gyr and a metallicity of [Fe/H] = 0.14 dex (metal-rich relative to the Sun). From Earth, Kepler-1927 shines at apparent V-band magnitude 13.312 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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