CD Cet b

Astrophysical Synthesis & Habitability Characterization

CD Cet b is a confirmed super-earth exoplanet orbiting the star CD Cet, located approximately 28.1 light-years (8.61 parsecs) from the Solar System. First announced in 2020 by Calar Alto Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 1.82 Earth radii and has a measured mass of 3.95 Earth masses. Combining its mass and radius yields a mean bulk density of 3.61 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.19 g⊕ (11.67 m/s²), and an escape velocity of 16.5 km/s.

In its orbital architecture around CD Cet, CD Cet b completes one full revolution every 2.291 Earth days at a semi-major axis of 0.0185 AU (an ultra-close orbit less than one-seventh of Mercury's 0.387 AU distance from the Sun, where strong stellar tidal forces typically induce synchronous rotation). Its mean orbital velocity is approximately 87.9 km/s (compared to Earth's 29.8 km/s).

⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 464 K (+191°C / +376°F) and receiving 8.60 S⊕ (~11,705 W/m²), CD Cet b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star CD Cet is classified as a low-mass red dwarf of spectral type M5.0 V with an effective photospheric temperature of 3,130 K, a radius of 0.175 R☉, a mass of 0.161 M☉, an estimated bolometric luminosity of 0.00264 L☉. Stellar evolution modeling indicates an estimated stellar age of 3 Gyr and a metallicity of [Fe/H] = 0.13 dex (metal-rich relative to the Sun). From Earth, CD Cet shines at apparent V-band magnitude 13.95 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.

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