Kepler-1915 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1915 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-1915, located approximately 4940.2 light-years (1514.66 parsecs) from the Solar System. First announced in 2021 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0779% across the stellar disk), this world measures 3.218 Earth radii (0.29 Jupiter radii) and has a measured mass of 10.4 Earth masses. Combining its mass and radius yields a mean bulk density of 1.72 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1 g⊕ (9.81 m/s²), and an escape velocity of 20.1 km/s.

In its orbital architecture around Kepler-1915, Kepler-1915 b completes one full revolution every 13.835 Earth days at a semi-major axis of 0.114 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 89.6 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 809 K (+536°C / +997°F) and receiving 101.05 S⊕ (~137,529 W/m²), Kepler-1915 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1915 is classified as a stellar host with an effective photospheric temperature of 6,020 K, a radius of 1.057 R☉, a mass of 1.03 M☉, an estimated bolometric luminosity of 1.317 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.06 dex (near-solar heavy-element abundance). From Earth, Kepler-1915 shines at apparent V-band magnitude 16.261 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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