WASP-55 b
WASP-55 b is a hot Jupiter orbiting WASP-55 in the constellation Virgo. It lies about 970 light-years from Earth and was discovered in 2012 using the transit method.
How Big Is WASP-55 b?
WASP-55 b has a radius of 14.73 times that of Earth, or 1.31 times the radius of Jupiter. Its mass is 186 times that of Earth, giving it a density of 0.34 g/cm³ — closer to gas planets like Jupiter (1.33 g/cm³).
Is WASP-55 b in the Habitable Zone?
The position of WASP-55 b relative to the habitable zone of WASP-55 cannot be precisely determined from the available orbital data.
Habitable zone of WASP-55: 0.893–2.088 AU (conservative: 1.131–1.980 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
See the full interactive habitable-zone view in the Exoplanet Explorer app ›
Temperature on WASP-55 b
The equilibrium temperature of WASP-55 b is about 1,342 K (1,069 °C) — hot enough to melt many metals. This estimate ignores any atmosphere, which could change surface temperatures dramatically — Earth's greenhouse effect adds about 33 °C. It receives 504 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on WASP-55 b — one full orbit around WASP-55 — lasts 4.47 Earth days, shorter than Mercury's 88-day year.
How Was WASP-55 b Discovered?
WASP-55 b was discovered in 2012 using the transit method, with observations from SuperWASP.
The transit method watches a star for the tiny, regular dip in brightness that occurs when a planet crosses in front of it. The depth and timing of these dips reveal the planet's size and orbital period.
How Far Away Is WASP-55 b?
WASP-55 b is 970.2 light-years (297.5 parsecs) from Earth. Light arriving here tonight left the planet around the year 1056. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 17,075,520 years to make the journey.
Earth Similarity Index
The Earth Similarity Index (ESI) scores how physically similar a planet is to Earth, from 0 to 1, based on radius, density, escape velocity and surface temperature. WASP-55 b scores 0.06, ranking #5,096 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: WASP-55
WASP-55 b belongs to a system of 2 stars; it orbits WASP-55.
WASP-55
- Surface temperature
- 6,096 K (Sun: 5,772 K)
- Mass
- 1.07 M☉
- Radius
- 1.09 R☉
- Age
- 3.1 billion years (Sun: 4.6)
Planetary System
WASP-55 b is the only planet known to orbit WASP-55 so far.
WASP-55 b — Complete Data
| Radius | 14.729 Earth radii (1.314 Jupiter radii) |
|---|---|
| Mass | 186.25 Earth masses (0.586 Jupiter masses) |
| Density | 0.34 g/cm³ (Earth: 5.51) |
| Orbital period | 4.47 days |
| Equilibrium temperature | 1,342 K (1,069 °C) |
| Stellar irradiation | 504.00× Earth |
| Earth Similarity Index | 0.06 |
| Distance from Earth | 970.2 light-years (297.5 parsecs) |
| Constellation | Virgo |
| Discovery method | Transit |
| Discovery facility | SuperWASP |
| Discovery year | 2012 |
Data: NASA Exoplanet Archive, last updated 2025-10-09. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About WASP-55 b
Is WASP-55 b habitable?
WASP-55 b is not known to orbit within the habitable zone of WASP-55, and as a hot Jupiter it is an unlikely candidate for life as we know it.
How far away is WASP-55 b?
WASP-55 b is about 970 light-years from Earth in the constellation Virgo. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 17,075,520 years to get there.
How big is WASP-55 b compared to Earth?
WASP-55 b has 14.73 times the radius of Earth and about 186 times its mass.
How long is a year on WASP-55 b?
One orbit around WASP-55 takes 4.5 Earth days — short enough that 82 of its years would fit into one Earth year.
Explore WASP-55 b in the app
Browse, filter and compare 6,000+ exoplanets on iPhone, iPad and Apple Watch — with habitable-zone views, widgets and offline data.
