Kepler-1517 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1517 b is a confirmed gas giant exoplanet orbiting the star Kepler-1517, located approximately 2763.5 light-years (847.3 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.2106% across the stellar disk), this world measures 9.76 Earth radii (0.87 Jupiter radii) and has a measured mass of 68.7 Earth masses (0.22 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.41 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.72 g⊕ (7.06 m/s²), and an escape velocity of 29.7 km/s.

In its orbital architecture around Kepler-1517, Kepler-1517 b completes one full revolution every 5.546 Earth days at a semi-major axis of 0.078 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 153 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 2336 K (+2063°C / +3745°F) and receiving 1,526.98 S⊕ (~2,078,224 W/m²), Kepler-1517 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1517 is classified as a stellar host with an effective photospheric temperature of 7,010 K, a radius of 1.95 R☉, a mass of 1.58 M☉, an estimated bolometric luminosity of 8.238 L☉. Stellar evolution modeling indicates an estimated stellar age of 1.38 Gyr and a metallicity of [Fe/H] = 0.01 dex (near-solar heavy-element abundance). From Earth, Kepler-1517 shines at apparent V-band magnitude 12.228 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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