Kepler-954 b

Astrophysical Synthesis & Habitability Characterization

Kepler-954 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-954, located approximately 703.9 light-years (215.81 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0783% across the stellar disk), this world measures 2.32 Earth radii and has a measured mass of 5.99 Earth masses. Combining its mass and radius yields a mean bulk density of 2.65 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-954, Kepler-954 b completes one full revolution every 16.782 Earth days at a semi-major axis of 0.1202 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 77.9 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 545 K (+272°C / +522°F) and receiving 21.53 S⊕ (~29,304 W/m²), Kepler-954 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-954 is classified as a stellar host with an effective photospheric temperature of 4,990 K, a radius of 0.76 R☉, a mass of 0.82 M☉, an estimated bolometric luminosity of 0.321 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.39 Gyr and a metallicity of [Fe/H] = 0.02 dex (near-solar heavy-element abundance). From Earth, Kepler-954 shines at apparent V-band magnitude 13.095 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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