Kepler-951 b

Astrophysical Synthesis & Habitability Characterization

Kepler-951 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-951, located approximately 1247.6 light-years (382.51 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.4929% across the stellar disk), this world measures 5.59 Earth radii (0.5 Jupiter radii) and has a measured mass of 26.7 Earth masses. Combining its mass and radius yields a mean bulk density of 0.84 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.85 g⊕ (8.34 m/s²), and an escape velocity of 24.4 km/s.

In its orbital architecture around Kepler-951, Kepler-951 b completes one full revolution every 71.525 Earth days at a semi-major axis of 0.3091 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 47 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.

☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 5.590 R⊕, Kepler-951 b exceeds the empirical ~1.8–2.2 R⊕ Fulton radius valley threshold, indicating a substantial hydrogen-helium or supercritical volatile envelope without a conventional solid terrestrial surface.

The host star Kepler-951 is classified as a stellar host with an effective photospheric temperature of 4,834 K, a radius of 0.73 R☉, a mass of 0.77 M☉, an estimated bolometric luminosity of 0.261 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.27 Gyr and a metallicity of [Fe/H] = -0.01 dex (near-solar heavy-element abundance). From Earth, Kepler-951 shines at apparent V-band magnitude 14.841 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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