CT Cha b

Astrophysical Synthesis & Habitability Characterization

CT Cha b is a confirmed gas giant exoplanet orbiting the star CT Cha, located approximately 622 light-years (190.72 parsecs) from the Solar System. First announced in 2007 by Paranal Observatory using the Imaging detection technique (resolved directly via high-contrast coronagraphic or interferometric imaging), this world measures 24.66 Earth radii (2.2 Jupiter radii) and has a measured mass of 5403 Earth masses (17 Jupiter masses). Combining its mass and radius yields a mean bulk density of 1.99 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 8.88 g⊕ (87.08 m/s²), and an escape velocity of 165.6 km/s.

⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 2600 K (+2327°C / +4221°F), CT Cha b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star CT Cha is classified as an orange K-type star of spectral type K5e with an effective photospheric temperature of 4,403 K, a radius of 1.6797 R☉, an estimated bolometric luminosity of 0.951 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.002 Gyr and a metallicity of [Fe/H] = -0.56 dex (metal-poor relative to the Sun). From Earth, CT Cha shines at apparent V-band magnitude 12.335 (faint and requiring research-grade or CCD telescopic photometry) in the Southern celestial hemisphere.

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