Kepler-1723 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1723 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-1723, located approximately 2646 light-years (811.28 parsecs) from the Solar System. First announced in 2021 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0683% across the stellar disk), this world measures 2.88 Earth radii and has a measured mass of 8.65 Earth masses. Combining its mass and radius yields a mean bulk density of 2 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.04 g⊕ (10.2 m/s²), and an escape velocity of 19.4 km/s.

In its orbital architecture around Kepler-1723, Kepler-1723 b completes one full revolution every 39.753 Earth days at a semi-major axis of 0.2249 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 61.5 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 568 K (+295°C / +563°F) and receiving 24.54 S⊕ (~33,399 W/m²), Kepler-1723 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1723 is classified as a stellar host with an effective photospheric temperature of 6,072 K, a radius of 1.01 R☉, a mass of 0.96 M☉, an estimated bolometric luminosity of 1.244 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.3 Gyr and a metallicity of [Fe/H] = -0.3 dex (metal-poor relative to the Sun). From Earth, Kepler-1723 shines at apparent V-band magnitude 14.383 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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