WASP-57 b
Astrophysical Synthesis & Habitability Characterization
WASP-57 b is a confirmed gas giant exoplanet orbiting the star WASP-57, located approximately 1299 light-years (398.28 parsecs) from the Solar System. First announced in 2012 by SuperWASP using the Transit detection technique (producing an estimated primary transit depth of 1.3548% across the stellar disk), this world measures 11.769 Earth radii (1.05 Jupiter radii) and has a measured mass of 204.683 Earth masses (0.64 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.69 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.48 g⊕ (14.51 m/s²), and an escape velocity of 46.6 km/s.
In its orbital architecture around WASP-57, WASP-57 b completes one full revolution every 2.839 Earth days at a semi-major axis of 0.03769 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 144.4 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 1338 K (+1065°C / +1949°F) and receiving 702.39 S⊕ (~955,946 W/m²), WASP-57 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star WASP-57 is classified as a solar-type yellow star of spectral type G6 with an effective photospheric temperature of 5,600 K, a radius of 0.927 R☉, a mass of 0.886 M☉, an estimated bolometric luminosity of 0.758 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.6 Gyr and a metallicity of [Fe/H] = -0.25 dex (metal-poor relative to the Sun). From Earth, WASP-57 shines at apparent V-band magnitude 12.913 (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-57 |
| Spectral Type | G6 |
| Effective Temp (Teff) | 5,600 K |
| Stellar Radius | 0.9270 R☉ |
| Stellar Mass | 0.8860 M☉ |
| Bolometric Luminosity | 0.758 L☉ |
| Metallicity [Fe/H] | -0.250 dex |
| Stellar Age | 2.600 Gyr |
| Apparent Magnitude | V: 12.913 · G: 12.729 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.037690 AU |
| Orbital Period | 2.839 days |
| Mean Orbital Velocity | 144.4 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 86.0500° |
| Mean Bulk Density | 0.69 g/cm³ (46.6 km/s vesc) |
| Insolation Flux | 702.3850 S⊕ (~955,946 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1299.000 LY (398.276 pc) |