WASP-8 c
Astrophysical Synthesis & Habitability Characterization
WASP-8 c is a confirmed gas giant exoplanet orbiting the star WASP-8, located approximately 293.4 light-years (89.96 parsecs) from the Solar System. First announced in 2013 by SuperWASP using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 12.5 Earth radii (1.12 Jupiter radii) and has a measured mass of 3003.37 Earth masses (9.45 Jupiter masses). Combining its mass and radius yields a mean bulk density of 8.48 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 19.22 g⊕ (188.48 m/s²), and an escape velocity of 173.4 km/s.
In its orbital architecture around WASP-8, WASP-8 c completes one full revolution every 4323 Earth days (11.84Julian years) at a semi-major axis of 5.28 AU (a wide outer-system orbit beyond Jupiter's 5.20 AU distance in our Solar System). Its mean orbital velocity is approximately 13.3 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 (Cryogenic Zone): With an equilibrium temperature of 117 K (-156°C / -249°F) and an incident flux of 0.03 S⊕ (~43 W/m²), surface water and volatile species on WASP-8 c would remain locked in cryogenic ice phases unless warmed by subsurface tidal or radiogenic heating.
The host star WASP-8 is classified as a solar-type yellow star of spectral type G8 V with an effective photospheric temperature of 5,690 K, a radius of 0.96 R☉, a mass of 1.04 M☉, an estimated bolometric luminosity of 0.867 L☉. Stellar evolution modeling indicates an estimated stellar age of 3 Gyr and a metallicity of [Fe/H] = 0.17 dex (metal-rich relative to the Sun). From Earth, WASP-8 shines at apparent V-band magnitude 9.789 (accessible to binoculars and small amateur telescopes) in the Southern celestial hemisphere. The WASP-8 system is a multi-planet architecture hosting 2 confirmed worlds, with WASP-8 c sharing its stellar neighborhood alongside WASP-8 b.
Methodology: Computed using the Schulze-Makuch et al. (2011) weighted metric comparing physical interior (radius, estimated density) and surface thermal regime (escape velocity, equilibrium temperature).
Discovery Facility: SuperWASP · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | WASP-8 |
| Spectral Type | G8 V |
| Effective Temp (Teff) | 5,690 K |
| Stellar Radius | 0.9600 R☉ |
| Stellar Mass | 1.0400 M☉ |
| Bolometric Luminosity | 0.867 L☉ |
| Metallicity [Fe/H] | 0.170 dex |
| Stellar Age | 3.000 Gyr |
| Apparent Magnitude | V: 9.789 · G: 9.612 |
| System Architecture | 2 Stars, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 5.280000 AU |
| Orbital Period | 4323 days |
| Mean Orbital Velocity | 13.3 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 8.48 g/cm³ (173.4 km/s vesc) |
| Insolation Flux | 0.0314 S⊕ (~43 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 293.400 LY (89.961 pc) |