WASP-55 b

Astrophysical Synthesis & Habitability Characterization

WASP-55 b is a confirmed gas giant exoplanet orbiting the star WASP-55, located approximately 970.2 light-years (297.46 parsecs) from the Solar System. First announced in 2012 by SuperWASP using the Transit detection technique (producing an estimated primary transit depth of 1.5347% across the stellar disk), this world measures 14.729 Earth radii (1.31 Jupiter radii) and has a measured mass of 186.247 Earth masses (0.59 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.32 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.86 g⊕ (8.43 m/s²), and an escape velocity of 39.8 km/s.

In its orbital architecture around WASP-55, WASP-55 b completes one full revolution every 4.466 Earth days at a semi-major axis of 0.0558 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 135.9 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 1342 K (+1069°C / +1956°F) and receiving 504.00 S⊕ (~685,944 W/m²), WASP-55 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.

The host star WASP-55 is classified as a stellar host with an effective photospheric temperature of 6,096 K, a radius of 1.09 R☉, a mass of 1.071 M☉, an estimated bolometric luminosity of 1.472 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.05 Gyr and a metallicity of [Fe/H] = -0.03 dex (near-solar heavy-element abundance). From Earth, WASP-55 shines at apparent V-band magnitude 11.753 (faint and requiring research-grade or CCD telescopic photometry) in the Southern celestial hemisphere.

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