Kepler-1552 b

Astrophysical Synthesis & Habitability Characterization

Kepler-1552 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-1552, located approximately 2508.5 light-years (769.1 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0843% across the stellar disk), this world measures 2.47 Earth radii and has a measured mass of 6.66 Earth masses. Combining its mass and radius yields a mean bulk density of 2.44 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 18.4 km/s.

In its orbital architecture around Kepler-1552, Kepler-1552 b completes one full revolution every 184.772 Earth days at a semi-major axis of 0.6011 AU (situated at an orbital separation between Mercury's 0.39 AU and Venus's 0.72 AU). Its mean orbital velocity is approximately 35.4 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.

☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 2.470 R⊕, Kepler-1552 b exceeds the empirical ~1.8–2.2 R⊕ Fulton radius valley threshold, indicating a substantial hydrogen-helium or supercritical volatile envelope without a conventional solid terrestrial surface.

The host star Kepler-1552 is classified as a stellar host with an effective photospheric temperature of 5,202 K, a radius of 0.78 R☉, a mass of 0.85 M☉, an estimated bolometric luminosity of 0.4 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.31 Gyr and a metallicity of [Fe/H] = -0.07 dex (near-solar heavy-element abundance). From Earth, Kepler-1552 shines at apparent V-band magnitude 15.203 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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