Kepler-1155 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1155 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-1155, located approximately 3681.4 light-years (1128.72 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0326% across the stellar disk), this world measures 2.03 Earth radii and has a measured mass of 4.78 Earth masses. Combining its mass and radius yields a mean bulk density of 3.15 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.16 g⊕ (11.38 m/s²), and an escape velocity of 17.2 km/s.

In its orbital architecture around Kepler-1155, Kepler-1155 b completes one full revolution every 33.47 Earth days at a semi-major axis of 0.2006 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 65.2 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 609 K (+336°C / +637°F) and receiving 32.52 S⊕ (~44,260 W/m²), Kepler-1155 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star Kepler-1155 is classified as a stellar host with an effective photospheric temperature of 5,842 K, a radius of 1.03 R☉, a mass of 1.03 M☉, an estimated bolometric luminosity of 1.109 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.72 Gyr and a metallicity of [Fe/H] = 0.04 dex (near-solar heavy-element abundance). From Earth, Kepler-1155 shines at apparent V-band magnitude 14.799 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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