WASP-186 b
WASP-186 b is a hot Jupiter orbiting the F star WASP-186 in the constellation Pisces. It lies about 908 light-years from Earth and was discovered in 2020 using the transit method.
How Big Is WASP-186 b?
WASP-186 b has a radius of 12.44 times that of Earth, or 1.11 times the radius of Jupiter. Its mass is 1,341 times that of Earth, giving it a density of 3.82 g/cm³ — between that of rocky and gaseous planets.
Is WASP-186 b in the Habitable Zone?
WASP-186 b orbits inside the inner edge of the habitable zone of WASP-186. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of WASP-186: 1.291–3.002 AU (conservative: 1.635–2.847 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 ›
Orbit and Year Length
A year on WASP-186 b — one full orbit around WASP-186 — lasts 5.03 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.060 AU — closer to its star than Mercury is to the Sun. Its orbit is highly elliptical (eccentricity 0.33), swinging dramatically closer to and farther from its star.
How Was WASP-186 b Discovered?
WASP-186 b was discovered in 2020 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-186 b?
WASP-186 b is 908.4 light-years (278.5 parsecs) from Earth. Light arriving here tonight left the planet around the year 1118. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 15,987,840 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-186 b scores 0.07, ranking #4,874 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: WASP-186
WASP-186
- Spectral type
- F
- Surface temperature
- 6,361 K (Sun: 5,772 K)
- Mass
- 1.22 M☉
- Radius
- 1.47 R☉
- Age
- 3.1 billion years (Sun: 4.6)
Planetary System
WASP-186 b is the only planet known to orbit WASP-186 so far.
WASP-186 b — Complete Data
| Radius | 12.442 Earth radii (1.110 Jupiter radii) |
|---|---|
| Mass | 1,341.24 Earth masses (4.220 Jupiter masses) |
| Density | 3.82 g/cm³ (Earth: 5.51) |
| Orbital period | 5.03 days |
| Orbital distance | 0.060 AU |
| Eccentricity | 0.330 |
| Earth Similarity Index | 0.07 |
| Distance from Earth | 908.4 light-years (278.5 parsecs) |
| Constellation | Pisces |
| Discovery method | Transit |
| Discovery facility | SuperWASP |
| Discovery year | 2020 |
Data: NASA Exoplanet Archive, last updated 2020-12-10. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About WASP-186 b
Is WASP-186 b habitable?
No — WASP-186 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is WASP-186 b?
WASP-186 b is about 908 light-years from Earth in the constellation Pisces. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 15,987,840 years to get there.
How big is WASP-186 b compared to Earth?
WASP-186 b has 12.44 times the radius of Earth and about 1,341 times its mass.
How long is a year on WASP-186 b?
One orbit around WASP-186 takes 5.0 Earth days — short enough that 73 of its years would fit into one Earth year.
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