Kepler-727 b

Astrophysical Synthesis & Habitability Characterization

Kepler-727 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-727, located approximately 2713.1 light-years (831.84 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0727% across the stellar disk), this world measures 2.53 Earth radii and has a measured mass of 6.94 Earth masses. Combining its mass and radius yields a mean bulk density of 2.36 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.08 g⊕ (10.59 m/s²), and an escape velocity of 18.5 km/s.

In its orbital architecture around Kepler-727, Kepler-727 b completes one full revolution every 5.154 Earth days at a semi-major axis of 0.0546 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 115.2 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 964 K (+691°C / +1276°F) and receiving 176.69 S⊕ (~240,468 W/m²), Kepler-727 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-727 is classified as a stellar host with an effective photospheric temperature of 5,441 K, a radius of 0.86 R☉, a mass of 0.89 M☉, an estimated bolometric luminosity of 0.582 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.79 Gyr and a metallicity of [Fe/H] = -0.01 dex (near-solar heavy-element abundance). From Earth, Kepler-727 shines at apparent V-band magnitude 15.453 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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