WASP-136 b

Astrophysical Synthesis & Habitability Characterization

WASP-136 b is a confirmed gas giant exoplanet orbiting the star WASP-136, located approximately 898.8 light-years (275.59 parsecs) from the Solar System. First announced in 2016 by SuperWASP using the Transit detection technique (producing an estimated primary transit depth of 0.4159% across the stellar disk), this world measures 16.813 Earth radii (1.5 Jupiter radii) and has a measured mass of 479.921 Earth masses (1.51 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.56 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.7 g⊕ (16.67 m/s²), and an escape velocity of 59.8 km/s.

In its orbital architecture around WASP-136, WASP-136 b completes one full revolution every 5.215 Earth days at a semi-major axis of 0.0661 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 137.9 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.

⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1630 K (+1357°C / +2475°F) and receiving 1,843.46 S⊕ (~2,508,954 W/m²), WASP-136 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star WASP-136 is classified as a warm F-type star of spectral type F with an effective photospheric temperature of 6,250 K, a radius of 2.3901 R☉, a mass of 1.41 M☉, an estimated bolometric luminosity of 7.821 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.62 Gyr and a metallicity of [Fe/H] = -0.18 dex (metal-poor relative to the Sun). From Earth, WASP-136 shines at apparent V-band magnitude 9.974 (accessible to binoculars and small amateur telescopes) in the Southern celestial hemisphere.

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