Kepler-584 b

Astrophysical Synthesis & Habitability Characterization

Kepler-584 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-584, located approximately 6030.1 light-years (1848.84 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0969% across the stellar disk), this world measures 4.21 Earth radii (0.38 Jupiter radii) and has a measured mass of 16.5 Earth masses. Combining its mass and radius yields a mean bulk density of 1.22 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.93 g⊕ (9.12 m/s²), and an escape velocity of 22.1 km/s.

In its orbital architecture around Kepler-584, Kepler-584 b completes one full revolution every 35.181 Earth days at a semi-major axis of 0.2281 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 70.5 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 664 K (+391°C / +736°F) and receiving 76.34 S⊕ (~103,897 W/m²), Kepler-584 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-584 is classified as a stellar host with an effective photospheric temperature of 6,195 K, a radius of 1.24 R☉, a mass of 1.17 M☉, an estimated bolometric luminosity of 2.032 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.88 Gyr and a metallicity of [Fe/H] = 0.02 dex (near-solar heavy-element abundance). From Earth, Kepler-584 shines at apparent V-band magnitude 14.973 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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