WASP-149 b
Astrophysical Synthesis & Habitability Characterization
WASP-149 b is a confirmed gas giant exoplanet orbiting the star WASP-149, located approximately 690.6 light-years (211.73 parsecs) from the Solar System. First announced in 2025 by SuperWASP using the Transit detection technique (producing an estimated primary transit depth of 1.6745% across the stellar disk), this world measures 15.244 Earth radii (1.36 Jupiter radii) and has a measured mass of 314.968 Earth masses (0.99 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.49 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.36 g⊕ (13.34 m/s²), and an escape velocity of 50.8 km/s.
In its orbital architecture around WASP-149, WASP-149 b completes one full revolution every 1.333 Earth days at a semi-major axis of 0.024 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 195.9 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 1855 K (+1582°C / +2880°F) and receiving 1,966.00 S⊕ (~2,675,726 W/m²), WASP-149 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star WASP-149 is classified as a stellar host with an effective photospheric temperature of 5,750 K, a radius of 1.08 R☉, a mass of 1.05 M☉, an estimated bolometric luminosity of 1.144 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.6 Gyr and a metallicity of [Fe/H] = 0 dex (near-solar heavy-element abundance). From Earth, WASP-149 shines at apparent V-band magnitude 11.687 (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-149 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,750 K |
| Stellar Radius | 1.0800 R☉ |
| Stellar Mass | 1.0500 M☉ |
| Bolometric Luminosity | 1.144 L☉ |
| Metallicity [Fe/H] | 0.000 dex |
| Stellar Age | 0.600 Gyr |
| Apparent Magnitude | V: 11.687 · G: 11.262 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.024000 AU |
| Orbital Period | 1.333 days |
| Mean Orbital Velocity | 195.9 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 83.0200° |
| Mean Bulk Density | 0.49 g/cm³ (50.8 km/s vesc) |
| Insolation Flux | 1966.0000 S⊕ (~2,675,726 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 690.600 LY (211.730 pc) |