WASP-23 b
Astrophysical Synthesis & Habitability Characterization
WASP-23 b is a confirmed gas giant exoplanet orbiting the star WASP-23, located approximately 676.7 light-years (207.49 parsecs) from the Solar System. First announced in 2010 by SuperWASP using the Transit detection technique (producing an estimated primary transit depth of 1.6699% across the stellar disk), this world measures 10.783 Earth radii (0.96 Jupiter radii) and has a measured mass of 280.95 Earth masses (0.88 Jupiter masses). Combining its mass and radius yields a mean bulk density of 1.24 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 2.42 g⊕ (23.73 m/s²), and an escape velocity of 57.1 km/s.
In its orbital architecture around WASP-23, WASP-23 b completes one full revolution every 2.944 Earth days at a semi-major axis of 0.0376 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 138.9 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.062 carries the world between 0.0353 AU at periapsis and 0.0399 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1077 K (+804°C / +1479°F) and receiving 317.43 S⊕ (~432,024 W/m²), WASP-23 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star WASP-23 is classified as a stellar host with an effective photospheric temperature of 5,150 K, a radius of 0.765 R☉, a mass of 0.78 M☉, an estimated bolometric luminosity of 0.369 L☉. Stellar evolution modeling indicates an estimated stellar age of 6.2 Gyr and a metallicity of [Fe/H] = -0.05 dex (near-solar heavy-element abundance). From Earth, WASP-23 shines at apparent V-band magnitude 12.539 (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-23 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,150 K |
| Stellar Radius | 0.7650 R☉ |
| Stellar Mass | 0.7800 M☉ |
| Bolometric Luminosity | 0.369 L☉ |
| Metallicity [Fe/H] | -0.050 dex |
| Stellar Age | 6.200 Gyr |
| Apparent Magnitude | V: 12.539 · G: 12.321 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.037600 AU |
| Orbital Period | 2.944 days |
| Mean Orbital Velocity | 138.9 km/s |
| Orbital Eccentricity (e) | 0.06200 |
| Orbital Inclination (i) | 88.3900° |
| Mean Bulk Density | 1.24 g/cm³ (57.1 km/s vesc) |
| Insolation Flux | 317.4314 S⊕ (~432,024 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 676.700 LY (207.490 pc) |