WASP-170 b

Astrophysical Synthesis & Habitability Characterization

WASP-170 b is a confirmed gas giant exoplanet orbiting the star WASP-170, located approximately 996.7 light-years (305.6 parsecs) from the Solar System. First announced in 2018 by SuperWASP-South using the Transit detection technique (producing an estimated primary transit depth of 1.4417% across the stellar disk), this world measures 12.285 Earth radii (1.1 Jupiter radii) and has a measured mass of 508.528 Earth masses (1.6 Jupiter masses). Combining its mass and radius yields a mean bulk density of 1.51 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 3.37 g⊕ (33.05 m/s²), and an escape velocity of 72 km/s.

In its orbital architecture around WASP-170, WASP-170 b completes one full revolution every 2.345 Earth days at a semi-major axis of 0.0337 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 156.4 km/s (compared to Earth's 29.8 km/s).

⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1422 K (+1149°C / +2100°F) and receiving 680.00 S⊕ (~925,480 W/m²), WASP-170 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star WASP-170 is classified as a stellar host with an effective photospheric temperature of 5,600 K, a radius of 0.938 R☉, a mass of 0.93 M☉, an estimated bolometric luminosity of 0.776 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = 0.22 dex (metal-rich relative to the Sun). From Earth, WASP-170 shines at apparent V-band magnitude 12.613 (faint and requiring research-grade or CCD telescopic photometry) in the Southern celestial hemisphere.

Discovery Facility: SuperWASP-South · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).