Kepler-1997 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1997 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-1997, located approximately 4900 light-years (1502.34 parsecs) from the Solar System. First announced in 2023 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0395% across the stellar disk), this world measures 2.28 Earth radii and has a measured mass of 5.82 Earth masses. Combining its mass and radius yields a mean bulk density of 2.71 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.12 g⊕ (10.98 m/s²), and an escape velocity of 17.9 km/s.

In its orbital architecture around Kepler-1997, Kepler-1997 b completes one full revolution every 26.758 Earth days at a semi-major axis of 0.1815 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 73.8 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 660 K (+387°C / +729°F) and receiving 44.86 S⊕ (~61,054 W/m²), Kepler-1997 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1997 is classified as a stellar host with an effective photospheric temperature of 6,215 K, a radius of 1.052 R☉, a mass of 1.111 M☉, an estimated bolometric luminosity of 1.481 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.06 dex (near-solar heavy-element abundance). From Earth, Kepler-1997 shines at apparent V-band magnitude 15.454 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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