WASP-72 b
Astrophysical Synthesis & Habitability Characterization
WASP-72 b is a confirmed gas giant exoplanet orbiting the star WASP-72, located approximately 1418 light-years (434.75 parsecs) from the Solar System. First announced in 2012 by SuperWASP using the Transit detection technique (producing an estimated primary transit depth of 0.3698% across the stellar disk), this world measures 14.46 Earth radii (1.29 Jupiter radii) and has a measured mass of 731.009 Earth masses (2.3 Jupiter masses). Combining its mass and radius yields a mean bulk density of 1.33 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 3.5 g⊕ (34.32 m/s²), and an escape velocity of 79.5 km/s.
In its orbital architecture around WASP-72, WASP-72 b completes one full revolution every 2.217 Earth days at a semi-major axis of 0.03711 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 182.1 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 2210 K (+1937°C / +3519°F) and receiving 6,233.79 S⊕ (~8,484,190 W/m²), WASP-72 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star WASP-72 is classified as a warm F-type star of spectral type F7 with an effective photospheric temperature of 6,250 K, a radius of 2.18 R☉, a mass of 2.78 M☉, an estimated bolometric luminosity of 6.506 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.2 Gyr and a metallicity of [Fe/H] = -0.06 dex (near-solar heavy-element abundance). From Earth, WASP-72 shines at apparent V-band magnitude 10.868 (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-72 |
| Spectral Type | F7 |
| Effective Temp (Teff) | 6,250 K |
| Stellar Radius | 2.1800 R☉ |
| Stellar Mass | 2.7800 M☉ |
| Bolometric Luminosity | 6.506 L☉ |
| Metallicity [Fe/H] | -0.060 dex |
| Stellar Age | 3.200 Gyr |
| Apparent Magnitude | V: 10.868 · G: 10.838 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.037110 AU |
| Orbital Period | 2.217 days |
| Mean Orbital Velocity | 182.1 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 86.8000° |
| Mean Bulk Density | 1.33 g/cm³ (79.5 km/s vesc) |
| Insolation Flux | 6233.7915 S⊕ (~8,484,190 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1418.000 LY (434.754 pc) |