Kepler-1618 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1618 b is a confirmed super-earth exoplanet orbiting the star Kepler-1618, located approximately 4009.3 light-years (1229.25 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0049% across the stellar disk), this world measures 1.26 Earth radii and has a measured mass of 2.13 Earth masses. Combining its mass and radius yields a mean bulk density of 5.87 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.34 g⊕ (13.14 m/s²), and an escape velocity of 14.5 km/s.

In its orbital architecture around Kepler-1618, Kepler-1618 b completes one full revolution every 6.108 Earth days at a semi-major axis of 0.07109 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 126.6 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 1267 K (+994°C / +1821°F) and receiving 903.91 S⊕ (~1,230,219 W/m²), Kepler-1618 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1618 is classified as a stellar host with an effective photospheric temperature of 6,620 K, a radius of 1.65 R☉, a mass of 1.41 M☉, an estimated bolometric luminosity of 4.691 L☉. Stellar evolution modeling indicates an estimated stellar age of 1.78 Gyr and a metallicity of [Fe/H] = 0.04 dex (near-solar heavy-element abundance). From Earth, Kepler-1618 shines at apparent V-band magnitude 13.672 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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