Kepler-1938 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1938 b is a confirmed super-earth exoplanet orbiting the star Kepler-1938, located approximately 1373.6 light-years (421.15 parsecs) from the Solar System. First announced in 2021 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0655% across the stellar disk), this world measures 1.828 Earth radii and has a measured mass of 4 Earth masses. Combining its mass and radius yields a mean bulk density of 3.61 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.2 g⊕ (11.77 m/s²), and an escape velocity of 16.5 km/s.

In its orbital architecture around Kepler-1938, Kepler-1938 b completes one full revolution every 13.063 Earth days at a semi-major axis of 0.0938 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 78.1 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 527 K (+254°C / +489°F) and receiving 18.25 S⊕ (~24,838 W/m²), Kepler-1938 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1938 is classified as a stellar host with an effective photospheric temperature of 4,522 K, a radius of 0.655 R☉, a mass of 0.646 M☉, an estimated bolometric luminosity of 0.161 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.22 dex (metal-poor relative to the Sun). From Earth, Kepler-1938 shines at apparent V-band magnitude 15.246 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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