Kepler-519 b

Astrophysical Synthesis & Habitability Characterization

Kepler-519 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-519, located approximately 804.3 light-years (246.61 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0579% across the stellar disk), this world measures 2.1 Earth radii and has a measured mass of 5.06 Earth masses. Combining its mass and radius yields a mean bulk density of 3.01 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.15 g⊕ (11.28 m/s²), and an escape velocity of 17.4 km/s.

In its orbital architecture around Kepler-519, Kepler-519 b completes one full revolution every 24.308 Earth days at a semi-major axis of 0.15932 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 71.3 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 532 K (+259°C / +498°F) and receiving 19.87 S⊕ (~27,043 W/m²), Kepler-519 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-519 is classified as a stellar host with an effective photospheric temperature of 5,260 K, a radius of 0.8 R☉, a mass of 0.89 M☉, an estimated bolometric luminosity of 0.44 L☉. Stellar evolution modeling indicates an estimated stellar age of 1.91 Gyr and a metallicity of [Fe/H] = 0.01 dex (near-solar heavy-element abundance). From Earth, Kepler-519 shines at apparent V-band magnitude 12.77 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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