WASP-189 b
WASP-189 b is a hot Jupiter orbiting WASP-189 in the constellation Libra. It lies about 325 light-years from Earth and was discovered in 2020 using the transit method.
How Big Is WASP-189 b?
WASP-189 b has a radius of 18.15 times that of Earth, or 1.62 times the radius of Jupiter. Its mass is 632 times that of Earth, giving it a density of 0.62 g/cm³ — closer to gas planets like Jupiter (1.33 g/cm³).
Is WASP-189 b in the Habitable Zone?
The position of WASP-189 b relative to the habitable zone of WASP-189 cannot be precisely determined from the available orbital data.
Temperature on WASP-189 b
The equilibrium temperature of WASP-189 b is about 3,353 K (3,080 °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.
Orbit and Year Length
A year on WASP-189 b — one full orbit around WASP-189 — lasts 2.72 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.051 AU — closer to its star than Mercury is to the Sun.
How Was WASP-189 b Discovered?
WASP-189 b was discovered in 2020 using the transit method, with observations from CHaracterising ExOPlanets Satellite (CHEOPS).
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-189 b?
WASP-189 b is 325.3 light-years (99.7 parsecs) from Earth. Light arriving here tonight left the planet around the year 1701. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 5,725,280 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-189 b scores 0.05, ranking #5,278 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: WASP-189
WASP-189
- Surface temperature
- 8,000 K (Sun: 5,772 K)
- Mass
- 2.03 M☉
- Radius
- 2.36 R☉
- Age
- 0.7 billion years (Sun: 4.6)
Planetary System
WASP-189 b is the only planet known to orbit WASP-189 so far.
WASP-189 b — Complete Data
| Radius | 18.147 Earth radii (1.619 Jupiter radii) |
|---|---|
| Mass | 632.48 Earth masses (1.990 Jupiter masses) |
| Density | 0.62 g/cm³ (Earth: 5.51) |
| Orbital period | 2.72 days |
| Orbital distance | 0.051 AU |
| Equilibrium temperature | 3,353 K (3,080 °C) |
| Earth Similarity Index | 0.05 |
| Distance from Earth | 325.3 light-years (99.7 parsecs) |
| Constellation | Libra |
| Discovery method | Transit |
| Discovery facility | CHaracterising ExOPlanets Satellite (CHEOPS) |
| Discovery year | 2020 |
Data: NASA Exoplanet Archive, last updated 2022-03-16. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About WASP-189 b
Is WASP-189 b habitable?
WASP-189 b is not known to orbit within the habitable zone of WASP-189, and as a hot Jupiter it is an unlikely candidate for life as we know it.
How far away is WASP-189 b?
WASP-189 b is about 325 light-years from Earth in the constellation Libra. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 5,725,280 years to get there.
How big is WASP-189 b compared to Earth?
WASP-189 b has 18.15 times the radius of Earth and about 632 times its mass.
How long is a year on WASP-189 b?
One orbit around WASP-189 takes 2.7 Earth days — short enough that 134 of its years would fit into one Earth year.
Explore WASP-189 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.
