ROXs 42 B b

Astrophysical Synthesis & Habitability Characterization

ROXs 42 B b is a confirmed gas giant exoplanet orbiting the star ROXs 42 B, located approximately 468.3 light-years (143.59 parsecs) from the Solar System. First announced in 2013 by Multiple Observatories using the Imaging detection technique (resolved directly via high-contrast coronagraphic or interferometric imaging), this world measures 12.5 Earth radii (1.12 Jupiter radii) and has a measured mass of 2860 Earth masses (9 Jupiter masses). Combining its mass and radius yields a mean bulk density of 8.07 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 18.3 g⊕ (179.46 m/s²), and an escape velocity of 169.2 km/s.

The planet follows a highly eccentric trajectory (e = 0.58, swinging from 65.94 AU at periapsis out to 248.06 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.

⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1975 K (+1702°C / +3096°F), ROXs 42 B b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star ROXs 42 B is classified as a low-mass red dwarf of spectral type M0 with an effective photospheric temperature of 3,433 K, a radius of 1.3366 R☉, a mass of 1 M☉, an estimated bolometric luminosity of 0.223 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.003 Gyr. From Earth, ROXs 42 B shines at apparent V-band magnitude 14.661 (faint and requiring research-grade or CCD telescopic photometry) in the Southern celestial hemisphere.

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