WASP-22 b
Astrophysical Synthesis & Habitability Characterization
WASP-22 b is a confirmed gas giant exoplanet orbiting the star WASP-22, located approximately 1036 light-years (317.65 parsecs) from the Solar System. First announced in 2010 by SuperWASP using the Transit detection technique (producing an estimated primary transit depth of 1.0391% across the stellar disk), this world measures 13.787 Earth radii (1.23 Jupiter radii) and has a measured mass of 212.946 Earth masses (0.67 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.45 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.12 g⊕ (10.98 m/s²), and an escape velocity of 44 km/s.
In its orbital architecture around WASP-22, WASP-22 b completes one full revolution every 3.533 Earth days at a semi-major axis of 0.047 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 144.7 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.02 (ranging from 0.0461 AU at periapsis to 0.0479 AU at apoapsis), the planet experiences minimal orbital distance variation.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1502 K (+1229°C / +2244°F) and receiving 837.70 S⊕ (~1,140,114 W/m²), WASP-22 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star WASP-22 is classified as a solar-type yellow star of spectral type G1 V with an effective photospheric temperature of 6,000 K, a radius of 1.24 R☉, a mass of 1.46 M☉, an estimated bolometric luminosity of 1.788 L☉. Stellar evolution modeling indicates an estimated stellar age of 3 Gyr and a metallicity of [Fe/H] = -0.05 dex (near-solar heavy-element abundance). From Earth, WASP-22 shines at apparent V-band magnitude 11.99 (faint and requiring research-grade or CCD telescopic photometry) in the Southern 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-22 |
| Spectral Type | G1 V |
| Effective Temp (Teff) | 6,000 K |
| Stellar Radius | 1.2400 R☉ |
| Stellar Mass | 1.4600 M☉ |
| Bolometric Luminosity | 1.788 L☉ |
| Metallicity [Fe/H] | -0.050 dex |
| Stellar Age | 3.000 Gyr |
| Apparent Magnitude | V: 11.990 · G: 11.582 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.047000 AU |
| Orbital Period | 3.533 days |
| Mean Orbital Velocity | 144.7 km/s |
| Orbital Eccentricity (e) | 0.02000 |
| Orbital Inclination (i) | 89.2000° |
| Mean Bulk Density | 0.45 g/cm³ (44 km/s vesc) |
| Insolation Flux | 837.7034 S⊕ (~1,140,114 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1036.000 LY (317.652 pc) |