WASP-145 A b
Astrophysical Synthesis & Habitability Characterization
WASP-145 A b is a confirmed gas giant exoplanet orbiting the star WASP-145 A, located approximately 297.8 light-years (91.3 parsecs) from the Solar System. First announced in 2018 by SuperWASP-South using the Transit detection technique (producing an estimated primary transit depth of 1.8498% across the stellar disk), this world measures 10.088 Earth radii (0.9 Jupiter radii) and has a measured mass of 282.869 Earth masses (0.89 Jupiter masses). Combining its mass and radius yields a mean bulk density of 1.52 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 2.78 g⊕ (27.26 m/s²), and an escape velocity of 59.2 km/s.
In its orbital architecture around WASP-145 A, WASP-145 A b completes one full revolution every 1.769 Earth days at a semi-major axis of 0.0261 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 160.5 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 1200 K (+927°C / +1701°F) and receiving 313.40 S⊕ (~426,539 W/m²), WASP-145 A b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star WASP-145 A is classified as an orange K-type star of spectral type K2 V with an effective photospheric temperature of 4,900 K, a radius of 0.68 R☉, a mass of 0.76 M☉, an estimated bolometric luminosity of 0.239 L☉. Stellar evolution modeling indicates an estimated stellar age of 6.99 Gyr and a metallicity of [Fe/H] = -0.04 dex (near-solar heavy-element abundance). From Earth, WASP-145 A shines at apparent V-band magnitude 11.636 (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-South · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | WASP-145 A |
| Spectral Type | K2 V |
| Effective Temp (Teff) | 4,900 K |
| Stellar Radius | 0.6800 R☉ |
| Stellar Mass | 0.7600 M☉ |
| Bolometric Luminosity | 0.239 L☉ |
| Metallicity [Fe/H] | -0.040 dex |
| Stellar Age | 6.990 Gyr |
| Apparent Magnitude | V: 11.636 · G: 11.358 |
| System Architecture | 2 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.026100 AU |
| Orbital Period | 1.769 days |
| Mean Orbital Velocity | 160.5 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 83.3000° |
| Mean Bulk Density | 1.52 g/cm³ (59.2 km/s vesc) |
| Insolation Flux | 313.4012 S⊕ (~426,539 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 297.800 LY (91.299 pc) |