WASP-171 b
Astrophysical Synthesis & Habitability Characterization
WASP-171 b is a confirmed gas giant exoplanet orbiting the star WASP-171, located approximately 2471.7 light-years (757.84 parsecs) from the Solar System. First announced in 2019 by WASP-South using the Transit detection technique (producing an estimated primary transit depth of 0.3785% across the stellar disk), this world measures 10.985 Earth radii (0.98 Jupiter radii) and has a measured mass of 344.528 Earth masses (1.08 Jupiter masses). Combining its mass and radius yields a mean bulk density of 1.43 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 2.86 g⊕ (28.05 m/s²), and an escape velocity of 62.6 km/s.
In its orbital architecture around WASP-171, WASP-171 b completes one full revolution every 3.819 Earth days at a semi-major axis of 0.0504 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 143.6 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 1642 K (+1369°C / +2496°F) and receiving 1,200.24 S⊕ (~1,633,527 W/m²), WASP-171 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star WASP-171 is classified as a solar-type yellow star of spectral type G0 with an effective photospheric temperature of 5,965 K, a radius of 1.637 R☉, a mass of 1.171 M☉, an estimated bolometric luminosity of 3.044 L☉. Stellar evolution modeling indicates an estimated stellar age of 5.908 Gyr and a metallicity of [Fe/H] = 0.04 dex (near-solar heavy-element abundance). From Earth, WASP-171 shines at apparent V-band magnitude 12.612 (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: WASP-South · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | WASP-171 |
| Spectral Type | G0 |
| Effective Temp (Teff) | 5,965 K |
| Stellar Radius | 1.6370 R☉ |
| Stellar Mass | 1.1710 M☉ |
| Bolometric Luminosity | 3.044 L☉ |
| Metallicity [Fe/H] | 0.040 dex |
| Stellar Age | 5.908 Gyr |
| Apparent Magnitude | V: 12.612 · G: 12.441 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.050400 AU |
| Orbital Period | 3.819 days |
| Mean Orbital Velocity | 143.6 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 88.3000° |
| Mean Bulk Density | 1.43 g/cm³ (62.6 km/s vesc) |
| Insolation Flux | 1200.2400 S⊕ (~1,633,527 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2471.700 LY (757.840 pc) |