WASP-47 e
Astrophysical Synthesis & Habitability Characterization
WASP-47 e is a confirmed super-earth exoplanet orbiting the star WASP-47, located approximately 863.6 light-years (264.78 parsecs) from the Solar System. First announced in 2015 by K2 using the Transit detection technique (producing an estimated primary transit depth of 0.0211% across the stellar disk), this world measures 1.83 Earth radii and has a measured mass of 9 Earth masses. Combining its mass and radius yields a mean bulk density of 8.1 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 2.69 g⊕ (26.38 m/s²), and an escape velocity of 24.8 km/s.
In its orbital architecture around WASP-47, WASP-47 e completes one full revolution every 0.79 Earth days at a semi-major axis of 0.01673 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 230.5 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 1992 K (+1719°C / +3126°F) and receiving 3,740.00 S⊕ (~5,090,140 W/m²), WASP-47 e orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star WASP-47 is classified as a solar-type yellow star of spectral type G9 with an effective photospheric temperature of 5,565 K, a radius of 1.156 R☉, a mass of 1.058 M☉, an estimated bolometric luminosity of 1.15 L☉. Stellar evolution modeling indicates an estimated stellar age of 6.5 Gyr and a metallicity of [Fe/H] = 0.43 dex (metal-rich relative to the Sun). From Earth, WASP-47 shines at apparent V-band magnitude 11.936 (faint and requiring research-grade or CCD telescopic photometry) in the Southern celestial hemisphere. The WASP-47 system is a multi-planet architecture hosting 4 confirmed worlds, with WASP-47 e sharing its stellar neighborhood alongside WASP-47 b, WASP-47 d, WASP-47 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: K2 · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | WASP-47 |
| Spectral Type | G9 |
| Effective Temp (Teff) | 5,565 K |
| Stellar Radius | 1.1560 R☉ |
| Stellar Mass | 1.0580 M☉ |
| Bolometric Luminosity | 1.15 L☉ |
| Metallicity [Fe/H] | 0.430 dex |
| Stellar Age | 6.500 Gyr |
| Apparent Magnitude | V: 11.936 · G: 11.789 |
| System Architecture | 1 Star, 4 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.016730 AU |
| Orbital Period | 0.79 days |
| Mean Orbital Velocity | 230.5 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 86.7300° |
| Mean Bulk Density | 8.1 g/cm³ (24.8 km/s vesc) |
| Insolation Flux | 3740.0000 S⊕ (~5,090,140 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 863.600 LY (264.780 pc) |