WASP-12 b
Astrophysical Synthesis & Habitability Characterization
WASP-12 b is a confirmed gas giant exoplanet orbiting the star WASP-12, located approximately 1393.5 light-years (427.25 parsecs) from the Solar System. First announced in 2008 by SuperWASP using the Transit detection technique (producing an estimated primary transit depth of 1.4277% across the stellar disk), this world measures 22.026 Earth radii (1.97 Jupiter radii) and has a measured mass of 467.21 Earth masses (1.47 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.24 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.96 g⊕ (9.41 m/s²), and an escape velocity of 51.5 km/s.
In its orbital architecture around WASP-12, WASP-12 b completes one full revolution every 1.091 Earth days at a semi-major axis of 0.0234 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 233.2 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.0447 (ranging from 0.0224 AU at periapsis to 0.0244 AU at apoapsis), the planet experiences minimal orbital distance variation.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 2601 K (+2328°C / +4222°F) and receiving 8,220.58 S⊕ (~11,188,215 W/m²), WASP-12 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star WASP-12 is classified as a stellar host with an effective photospheric temperature of 6,265 K, a radius of 1.69 R☉, a mass of 1.325 M☉, an estimated bolometric luminosity of 3.948 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.05 Gyr and a metallicity of [Fe/H] = 0.12 dex (metal-rich relative to the Sun). From Earth, WASP-12 shines at apparent V-band magnitude 11.569 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.
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-12 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,265 K |
| Stellar Radius | 1.6900 R☉ |
| Stellar Mass | 1.3250 M☉ |
| Bolometric Luminosity | 3.948 L☉ |
| Metallicity [Fe/H] | 0.120 dex |
| Stellar Age | 3.050 Gyr |
| Apparent Magnitude | V: 11.569 · G: 11.500 |
| System Architecture | 3 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.023400 AU |
| Orbital Period | 1.091 days |
| Mean Orbital Velocity | 233.2 km/s |
| Orbital Eccentricity (e) | 0.04470 |
| Orbital Inclination (i) | 81.8000° |
| Mean Bulk Density | 0.24 g/cm³ (51.5 km/s vesc) |
| Insolation Flux | 8220.5840 S⊕ (~11,188,215 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1393.500 LY (427.246 pc) |