WASP-45 b
WASP-45 b is a hot Jupiter orbiting WASP-45 in the constellation Sculptor. It lies about 689 light-years from Earth and was discovered in 2011 using the transit method.
How Big Is WASP-45 b?
WASP-45 b has a radius of 10.60 times that of Earth, or 0.95 times the radius of Jupiter. Its mass is 306 times that of Earth, giving it a density of 1.42 g/cm³ — closer to gas planets like Jupiter (1.33 g/cm³).
Is WASP-45 b in the Habitable Zone?
WASP-45 b orbits inside the inner edge of the habitable zone of WASP-45. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of WASP-45: 0.528–1.270 AU (conservative: 0.669–1.204 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Temperature on WASP-45 b
The equilibrium temperature of WASP-45 b is about 1,153 K (880 °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 294 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on WASP-45 b — one full orbit around WASP-45 — lasts 3.13 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.040 AU — closer to its star than Mercury is to the Sun.
How Was WASP-45 b Discovered?
WASP-45 b was discovered in 2011 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-45 b?
WASP-45 b is 688.8 light-years (211.2 parsecs) from Earth. Light arriving here tonight left the planet around the year 1338. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 12,122,880 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-45 b scores 0.09, ranking #4,559 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: WASP-45
WASP-45 b belongs to a system of 2 stars; it orbits WASP-45.
WASP-45
- Surface temperature
- 5,150 K (Sun: 5,772 K)
- Mass
- 0.85 M☉
- Radius
- 0.86 R☉
- Luminosity
- 0.4618 L☉
Planetary System
WASP-45 b is the only planet known to orbit WASP-45 so far.
WASP-45 b — Complete Data
| Radius | 10.604 Earth radii (0.946 Jupiter radii) |
|---|---|
| Mass | 306.39 Earth masses (0.964 Jupiter masses) |
| Density | 1.42 g/cm³ (Earth: 5.51) |
| Orbital period | 3.13 days |
| Orbital distance | 0.040 AU |
| Equilibrium temperature | 1,153 K (880 °C) |
| Stellar irradiation | 294.00× Earth |
| Earth Similarity Index | 0.09 |
| Distance from Earth | 688.8 light-years (211.2 parsecs) |
| Constellation | Sculptor |
| Discovery method | Transit |
| Discovery facility | SuperWASP |
| Discovery year | 2011 |
Data: NASA Exoplanet Archive, last updated 2019-09-20. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About WASP-45 b
Is WASP-45 b habitable?
No — WASP-45 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is WASP-45 b?
WASP-45 b is about 689 light-years from Earth in the constellation Sculptor. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 12,122,880 years to get there.
How big is WASP-45 b compared to Earth?
WASP-45 b has 10.60 times the radius of Earth and about 306 times its mass.
How long is a year on WASP-45 b?
One orbit around WASP-45 takes 3.1 Earth days — short enough that 117 of its years would fit into one Earth year.
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