WASP-153 b
Astrophysical Synthesis & Habitability Characterization
WASP-153 b is a confirmed gas giant exoplanet orbiting the star WASP-153, located approximately 1990.1 light-years (610.18 parsecs) from the Solar System. First announced in 2017 by SuperWASP using the Transit detection technique (producing an estimated primary transit depth of 0.8477% across the stellar disk), this world measures 17.374 Earth radii (1.55 Jupiter radii) and has a measured mass of 123.954 Earth masses (0.39 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.13 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.41 g⊕ (4.02 m/s²), and an escape velocity of 29.9 km/s.
In its orbital architecture around WASP-153, WASP-153 b completes one full revolution every 3.333 Earth days at a semi-major axis of 0.048 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 156.7 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.009 (ranging from 0.0476 AU at periapsis to 0.0484 AU at apoapsis), the planet experiences minimal orbital distance variation.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1700 K (+1427°C / +2601°F) and receiving 1,400.00 S⊕ (~1,905,400 W/m²), WASP-153 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star WASP-153 is classified as a solar-type yellow star of spectral type G0 with an effective photospheric temperature of 5,914 K, a radius of 1.73 R☉, a mass of 1.336 M☉, an estimated bolometric luminosity of 3.285 L☉. Stellar evolution modeling indicates an estimated stellar age of 4 Gyr and a metallicity of [Fe/H] = 0.34 dex (metal-rich relative to the Sun). From Earth, WASP-153 shines at apparent V-band magnitude 12.591 (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-153 |
| Spectral Type | G0 |
| Effective Temp (Teff) | 5,914 K |
| Stellar Radius | 1.7300 R☉ |
| Stellar Mass | 1.3360 M☉ |
| Bolometric Luminosity | 3.285 L☉ |
| Metallicity [Fe/H] | 0.340 dex |
| Stellar Age | 4.000 Gyr |
| Apparent Magnitude | V: 12.591 · G: 12.497 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.048000 AU |
| Orbital Period | 3.333 days |
| Mean Orbital Velocity | 156.7 km/s |
| Orbital Eccentricity (e) | 0.00900 |
| Orbital Inclination (i) | 84.1000° |
| Mean Bulk Density | 0.13 g/cm³ (29.9 km/s vesc) |
| Insolation Flux | 1400.0000 S⊕ (~1,905,400 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1990.100 LY (610.176 pc) |