Kepler-1577 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1577 b is a confirmed terrestrial exoplanet orbiting the star Kepler-1577, located approximately 1663.5 light-years (510.03 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0196% across the stellar disk), this world measures 1.13 Earth radii and has a measured mass of 1.51 Earth masses. Combining its mass and radius yields a mean bulk density of 5.77 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.18 g⊕ (11.57 m/s²), and an escape velocity of 12.9 km/s.

In its orbital architecture around Kepler-1577, Kepler-1577 b completes one full revolution every 6.306 Earth days at a semi-major axis of 0.0657 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 113.4 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 1125 K (+852°C / +1566°F) and receiving 57.75 S⊕ (~78,599 W/m²), Kepler-1577 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1577 is classified as a stellar host with an effective photospheric temperature of 4,862 K, a radius of 0.74 R☉, a mass of 0.78 M☉, an estimated bolometric luminosity of 0.275 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.27 Gyr and a metallicity of [Fe/H] = 0 dex (near-solar heavy-element abundance). From Earth, Kepler-1577 shines at apparent V-band magnitude 15.228 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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