WASP-159 b
WASP-159 b is a hot Jupiter orbiting the F9 star WASP-159 in the constellation Caelum. It lies about 2,333 light-years from Earth and was discovered in 2018 using the transit method.
How Big Is WASP-159 b?
WASP-159 b has a radius of 15.47 times that of Earth, or 1.38 times the radius of Jupiter. Its mass is 175 times that of Earth, giving it a density of 0.28 g/cm³ — closer to gas planets like Jupiter (1.33 g/cm³).
Is WASP-159 b in the Habitable Zone?
WASP-159 b orbits inside the inner edge of the habitable zone of WASP-159. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of WASP-159: 1.740–4.066 AU (conservative: 2.204–3.855 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Temperature on WASP-159 b
The equilibrium temperature of WASP-159 b is about 1,850 K (1,577 °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-159 b — one full orbit around WASP-159 — lasts 3.84 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.054 AU — closer to its star than Mercury is to the Sun.
How Was WASP-159 b Discovered?
WASP-159 b was discovered in 2018 using the transit method, with observations from SuperWASP-South.
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-159 b?
WASP-159 b is 2,333.3 light-years (715.4 parsecs) from Earth. Light arriving here tonight left the planet about 2,333 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 41,066,080 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-159 b scores 0.06, ranking #5,157 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: WASP-159
WASP-159
- Spectral type
- F9
- Surface temperature
- 6,120 K (Sun: 5,772 K)
- Mass
- 1.41 M☉
- Radius
- 2.11 R☉
- Age
- 3.4 billion years (Sun: 4.6)
Planetary System
WASP-159 b is the only planet known to orbit WASP-159 so far.
WASP-159 b — Complete Data
| Radius | 15.468 Earth radii (1.380 Jupiter radii) |
|---|---|
| Mass | 174.81 Earth masses (0.550 Jupiter masses) |
| Density | 0.28 g/cm³ (Earth: 5.51) |
| Orbital period | 3.84 days |
| Orbital distance | 0.054 AU |
| Equilibrium temperature | 1,850 K (1,577 °C) |
| Earth Similarity Index | 0.06 |
| Distance from Earth | 2,333.3 light-years (715.4 parsecs) |
| Constellation | Caelum |
| Discovery method | Transit |
| Discovery facility | SuperWASP-South |
| Discovery year | 2018 |
Data: NASA Exoplanet Archive, last updated 2018-10-24. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About WASP-159 b
Is WASP-159 b habitable?
No — WASP-159 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is WASP-159 b?
WASP-159 b is about 2,333 light-years from Earth in the constellation Caelum. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 41,066,080 years to get there.
How big is WASP-159 b compared to Earth?
WASP-159 b has 15.47 times the radius of Earth and about 175 times its mass.
How long is a year on WASP-159 b?
One orbit around WASP-159 takes 3.8 Earth days — short enough that 95 of its years would fit into one Earth year.
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