Kepler-441 b

Astrophysical Synthesis & Habitability Characterization

Kepler-441 b is a confirmed super-earth exoplanet orbiting the star Kepler-441, located approximately 874.1 light-years (268 parsecs) from the Solar System. First announced in 2015 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0747% across the stellar disk), this world measures 1.64 Earth radii and has a measured mass of 3.33 Earth masses. Combining its mass and radius yields a mean bulk density of 4.16 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.24 g⊕ (12.16 m/s²), and an escape velocity of 15.9 km/s.

In its orbital architecture around Kepler-441, Kepler-441 b completes one full revolution every 207.248 Earth days at a semi-major axis of 0.64 AU (situated at an orbital separation between Mercury's 0.39 AU and Venus's 0.72 AU). Its mean orbital velocity is approximately 33.6 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.1 carries the world between 0.576 AU at periapsis and 0.704 AU at apoapsis, driving measurable seasonal insolation cycles.

ℹ️ Thermal & Atmospheric Regime: Current photometric and spectroscopic constraints for Kepler-441 b place it outside the conservative habitable zone definition pending further atmospheric characterization.

The host star Kepler-441 is classified as a stellar host with an effective photospheric temperature of 4,340 K, a radius of 0.55 R☉, a mass of 0.572 M☉, an estimated bolometric luminosity of 0.096 L☉. Stellar evolution modeling indicates an estimated stellar age of 1.9 Gyr and a metallicity of [Fe/H] = -0.57 dex (metal-poor relative to the Sun). From Earth, Kepler-441 shines at apparent V-band magnitude 15.567 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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