WASP-161 b
WASP-161 b is a hot Jupiter orbiting WASP-161 in the constellation Puppis. It lies about 1,119 light-years from Earth and was discovered in 2018 using the transit method.
How Big Is WASP-161 b?
WASP-161 b has a radius of 12.81 times that of Earth, or 1.14 times the radius of Jupiter. Its mass is 791 times that of Earth, giving it a density of 2.20 g/cm³ — between that of rocky and gaseous planets.
Is WASP-161 b in the Habitable Zone?
WASP-161 b orbits inside the inner edge of the habitable zone of WASP-161. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of WASP-161: 1.523–3.540 AU (conservative: 1.929–3.357 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Temperature on WASP-161 b
The equilibrium temperature of WASP-161 b is about 1,557 K (1,284 °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 990 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on WASP-161 b — one full orbit around WASP-161 — lasts 5.41 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.067 AU — closer to its star than Mercury is to the Sun.
How Was WASP-161 b Discovered?
WASP-161 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-161 b?
WASP-161 b is 1,119.0 light-years (343.1 parsecs) from Earth. Light arriving here tonight left the planet about 1,119 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 19,694,400 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-161 b scores 0.07, ranking #4,928 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: WASP-161
WASP-161
- Surface temperature
- 6,400 K (Sun: 5,772 K)
- Mass
- 1.39 M☉
- Radius
- 1.71 R☉
- Luminosity
- 4.4400 L☉
Planetary System
WASP-161 b is the only planet known to orbit WASP-161 so far.
WASP-161 b — Complete Data
| Radius | 12.812 Earth radii (1.143 Jupiter radii) |
|---|---|
| Mass | 791.40 Earth masses (2.490 Jupiter masses) |
| Density | 2.20 g/cm³ (Earth: 5.51) |
| Orbital period | 5.41 days |
| Orbital distance | 0.067 AU |
| Equilibrium temperature | 1,557 K (1,284 °C) |
| Stellar irradiation | 990.00× Earth |
| Earth Similarity Index | 0.07 |
| Distance from Earth | 1,119.0 light-years (343.1 parsecs) |
| Constellation | Puppis |
| Discovery method | Transit |
| Discovery facility | SuperWASP-South |
| Discovery year | 2018 |
Data: NASA Exoplanet Archive, last updated 2018-12-11. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About WASP-161 b
Is WASP-161 b habitable?
No — WASP-161 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is WASP-161 b?
WASP-161 b is about 1,119 light-years from Earth in the constellation Puppis. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 19,694,400 years to get there.
How big is WASP-161 b compared to Earth?
WASP-161 b has 12.81 times the radius of Earth and about 791 times its mass.
How long is a year on WASP-161 b?
One orbit around WASP-161 takes 5.4 Earth days — short enough that 68 of its years would fit into one Earth year.
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