Kepler-1984 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1984 b is a confirmed gas giant exoplanet orbiting the star Kepler-1984. First announced in 2023 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 2.2097% across the stellar disk), this world measures 6.81 Earth radii (0.61 Jupiter radii) and has a measured mass of 37.3 Earth masses (0.12 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.65 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.8 g⊕ (7.85 m/s²), and an escape velocity of 26.2 km/s.

In its orbital architecture around Kepler-1984, Kepler-1984 b completes one full revolution every 1.993 Earth days at a semi-major axis of 0.0238 AU (an ultra-close orbit less than one-seventh of Mercury's 0.387 AU distance from the Sun, where strong stellar tidal forces typically induce synchronous rotation). Its mean orbital velocity is approximately 129.9 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 675 K (+402°C / +756°F) and receiving 48.82 S⊕ (~66,444 W/m²), Kepler-1984 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1984 is classified as a stellar host with an effective photospheric temperature of 3,638 K, a radius of 0.42 R☉, a mass of 0.45 M☉, an estimated bolometric luminosity of 0.028 L☉. Stellar evolution modeling indicates an estimated stellar age of 13.8 Gyr and a metallicity of [Fe/H] = -0.14 dex (metal-poor relative to the Sun). From Earth, Kepler-1984 shines at apparent V-band magnitude 16.192 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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