Kepler-1726 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1726 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-1726, located approximately 1273.8 light-years (390.55 parsecs) from the Solar System. First announced in 2021 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0819% across the stellar disk), this world measures 2.509 Earth radii and has a measured mass of 6.84 Earth masses. Combining its mass and radius yields a mean bulk density of 2.39 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.09 g⊕ (10.69 m/s²), and an escape velocity of 18.5 km/s.

In its orbital architecture around Kepler-1726, Kepler-1726 b completes one full revolution every 18.396 Earth days at a semi-major axis of 0.12794 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 75.7 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 582 K (+309°C / +588°F) and receiving 24.00 S⊕ (~32,664 W/m²), Kepler-1726 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1726 is classified as a stellar host with an effective photospheric temperature of 5,316 K, a radius of 0.804 R☉, a mass of 0.876 M☉, an estimated bolometric luminosity of 0.463 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.51 Gyr and a metallicity of [Fe/H] = 0 dex (near-solar heavy-element abundance). From Earth, Kepler-1726 shines at apparent V-band magnitude 13.851 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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