HD 189733 b
HD 189733 b is a hot Jupiter orbiting HD 189733 in the constellation Vulpecula. It lies about 65 light-years from Earth and was discovered in 2005 using the radial velocity method.
How Big Is HD 189733 b?
HD 189733 b has a radius of 12.67 times that of Earth, or 1.13 times the radius of Jupiter. Its mass is 359 times that of Earth.
Is HD 189733 b in the Habitable Zone?
The position of HD 189733 b relative to the habitable zone of HD 189733 cannot be precisely determined from the available orbital data.
Habitable zone of HD 189733: 0.448–1.081 AU (conservative: 0.567–1.025 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 HD 189733 b — one full orbit around HD 189733 — lasts 2.22 Earth days, shorter than Mercury's 88-day year.
How Was HD 189733 b Discovered?
HD 189733 b was discovered in 2005 using the radial velocity method, with observations from Haute-Provence Observatory.
The radial velocity method measures the subtle wobble of a star caused by the gravitational pull of an orbiting planet, visible as periodic shifts in the star's light spectrum. The size of the wobble reveals the planet's minimum mass.
How Far Away Is HD 189733 b?
HD 189733 b is 64.5 light-years (19.8 parsecs) from Earth. Light arriving here tonight left the planet around the year 1962. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 1,135,200 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. HD 189733 b scores 0.07, ranking #4,845 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: HD 189733
HD 189733 b belongs to a system of 2 stars; it orbits HD 189733.
HD 189733
- Surface temperature
- 5,052 K (Sun: 5,772 K)
- Mass
- 0.79 M☉
- Radius
- 0.75 R☉
Planetary System
HD 189733 b is the only planet known to orbit HD 189733 so far.
HD 189733 b — Complete Data
| Radius | 12.666 Earth radii (1.130 Jupiter radii) |
|---|---|
| Mass | 359.15 Earth masses (1.130 Jupiter masses) |
| Orbital period | 2.22 days |
| Earth Similarity Index | 0.07 |
| Distance from Earth | 64.5 light-years (19.8 parsecs) |
| Constellation | Vulpecula |
| Discovery method | Radial Velocity |
| Discovery facility | Haute-Provence Observatory |
| Discovery year | 2005 |
Data: NASA Exoplanet Archive, last updated 2018-12-03. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HD 189733 b
Is HD 189733 b habitable?
HD 189733 b is not known to orbit within the habitable zone of HD 189733, and as a hot Jupiter it is an unlikely candidate for life as we know it.
How far away is HD 189733 b?
HD 189733 b is about 65 light-years from Earth in the constellation Vulpecula. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 1,135,200 years to get there.
How big is HD 189733 b compared to Earth?
HD 189733 b has 12.67 times the radius of Earth and about 359 times its mass.
How long is a year on HD 189733 b?
One orbit around HD 189733 takes 2.2 Earth days — short enough that 165 of its years would fit into one Earth year.
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