WASP-84 b
Astrophysical Synthesis & Habitability Characterization
WASP-84 b is a confirmed gas giant exoplanet orbiting the star WASP-84, located approximately 328.1 light-years (100.59 parsecs) from the Solar System. First announced in 2014 by SuperWASP using the Transit detection technique (producing an estimated primary transit depth of 1.6376% across the stellar disk), this world measures 10.72 Earth radii (0.96 Jupiter radii) and has a measured mass of 220 Earth masses (0.69 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.98 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.91 g⊕ (18.73 m/s²), and an escape velocity of 50.7 km/s.
In its orbital architecture around WASP-84, WASP-84 b completes one full revolution every 8.523 Earth days at a semi-major axis of 0.0778 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 99.3 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 732 K (+459°C / +858°F) and receiving 34.70 S⊕ (~47,220 W/m²), WASP-84 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star WASP-84 is classified as an orange K-type star of spectral type K0 with an effective photospheric temperature of 5,280 K, a radius of 0.768 R☉, a mass of 0.853 M☉, an estimated bolometric luminosity of 0.411 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.1 Gyr and a metallicity of [Fe/H] = 0 dex (near-solar heavy-element abundance). From Earth, WASP-84 shines at apparent V-band magnitude 10.825 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The WASP-84 system is a multi-planet architecture hosting 2 confirmed worlds, with WASP-84 b sharing its stellar neighborhood alongside WASP-84 c.
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-84 |
| Spectral Type | K0 |
| Effective Temp (Teff) | 5,280 K |
| Stellar Radius | 0.7680 R☉ |
| Stellar Mass | 0.8530 M☉ |
| Bolometric Luminosity | 0.411 L☉ |
| Metallicity [Fe/H] | 0.000 dex |
| Stellar Age | 2.100 Gyr |
| Apparent Magnitude | V: 10.825 · G: 10.575 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.077800 AU |
| Orbital Period | 8.523 days |
| Mean Orbital Velocity | 99.3 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 88.2920° |
| Mean Bulk Density | 0.98 g/cm³ (50.7 km/s vesc) |
| Insolation Flux | 34.6952 S⊕ (~47,220 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 328.100 LY (100.588 pc) |