Kepler-1828 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1828 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-1828, located approximately 2843.5 light-years (871.81 parsecs) from the Solar System. First announced in 2021 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0466% across the stellar disk), this world measures 2.116 Earth radii and has a measured mass of 5.13 Earth masses. Combining its mass and radius yields a mean bulk density of 2.99 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-1828, Kepler-1828 b completes one full revolution every 10.274 Earth days at a semi-major axis of 0.0924 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 97.8 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 799 K (+526°C / +979°F) and receiving 96.27 S⊕ (~131,023 W/m²), Kepler-1828 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1828 is classified as a stellar host with an effective photospheric temperature of 5,806 K, a radius of 0.899 R☉, a mass of 0.996 M☉, an estimated bolometric luminosity of 0.824 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.4 Gyr and a metallicity of [Fe/H] = -0.04 dex (near-solar heavy-element abundance). From Earth, Kepler-1828 shines at apparent V-band magnitude 14.985 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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