WASP-186 b
Astrophysical Synthesis & Habitability Characterization
WASP-186 b is a confirmed gas giant exoplanet orbiting the star WASP-186, located approximately 908.4 light-years (278.51 parsecs) from the Solar System. First announced in 2020 by SuperWASP using the Transit detection technique (producing an estimated primary transit depth of 0.6021% across the stellar disk), this world measures 12.442 Earth radii (1.11 Jupiter radii) and has a measured mass of 1341.243 Earth masses (4.22 Jupiter masses). Combining its mass and radius yields a mean bulk density of 3.84 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 8.66 g⊕ (84.93 m/s²), and an escape velocity of 116.1 km/s.
In its orbital architecture around WASP-186, WASP-186 b completes one full revolution every 5.027 Earth days at a semi-major axis of 0.06 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 129.9 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.33, swinging from 0.0402 AU at periapsis out to 0.0798 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1378 K (+1105°C / +2021°F) and receiving 853.14 S⊕ (~1,161,117 W/m²), WASP-186 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star WASP-186 is classified as a warm F-type star of spectral type F with an effective photospheric temperature of 6,361 K, a radius of 1.47 R☉, a mass of 1.22 M☉, an estimated bolometric luminosity of 3.174 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.1 Gyr and a metallicity of [Fe/H] = -0.08 dex (near-solar heavy-element abundance). From Earth, WASP-186 shines at apparent V-band magnitude 10.81 (faint and requiring research-grade or CCD telescopic photometry) in the Northern 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-186 |
| Spectral Type | F |
| Effective Temp (Teff) | 6,361 K |
| Stellar Radius | 1.4700 R☉ |
| Stellar Mass | 1.2200 M☉ |
| Bolometric Luminosity | 3.174 L☉ |
| Metallicity [Fe/H] | -0.080 dex |
| Stellar Age | 3.100 Gyr |
| Apparent Magnitude | V: 10.810 · G: 10.651 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.060000 AU |
| Orbital Period | 5.027 days |
| Mean Orbital Velocity | 129.9 km/s |
| Orbital Eccentricity (e) | 0.33000 |
| Orbital Inclination (i) | 83.5900° |
| Mean Bulk Density | 3.84 g/cm³ (116.1 km/s vesc) |
| Insolation Flux | 853.1355 S⊕ (~1,161,117 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 908.400 LY (278.514 pc) |