HD 149026 b
HD 149026 b is a hot Jupiter orbiting HD 149026 in the constellation Hercules. It lies about 247 light-years from Earth and was discovered in 2005 using the radial velocity method.
How Big Is HD 149026 b?
HD 149026 b has a radius of 8.29 times that of Earth, or 0.74 times the radius of Jupiter. Its mass is 121 times that of Earth.
Is HD 149026 b in the Habitable Zone?
The position of HD 149026 b relative to the habitable zone of HD 149026 cannot be precisely determined from the available orbital data.
Habitable zone of HD 149026: 1.181–2.757 AU (conservative: 1.496–2.614 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 149026 b — one full orbit around HD 149026 — lasts 2.88 Earth days, shorter than Mercury's 88-day year.
How Was HD 149026 b Discovered?
HD 149026 b was discovered in 2005 using the radial velocity method, with observations from Subaru Telescope.
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 149026 b?
HD 149026 b is 247.4 light-years (75.9 parsecs) from Earth. Light arriving here tonight left the planet around the year 1779. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 4,354,240 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 149026 b scores 0.10, ranking #4,425 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: HD 149026
HD 149026
- Surface temperature
- 6,179 K (Sun: 5,772 K)
- Mass
- 1.42 M☉
- Radius
- 1.41 R☉
Planetary System
HD 149026 b is the only planet known to orbit HD 149026 so far.
HD 149026 b — Complete Data
| Radius | 8.295 Earth radii (0.740 Jupiter radii) |
|---|---|
| Mass | 120.78 Earth masses (0.380 Jupiter masses) |
| Orbital period | 2.88 days |
| Earth Similarity Index | 0.10 |
| Distance from Earth | 247.4 light-years (75.9 parsecs) |
| Constellation | Hercules |
| Discovery method | Radial Velocity |
| Discovery facility | Subaru Telescope |
| Discovery year | 2005 |
Data: NASA Exoplanet Archive, last updated 2018-04-25. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HD 149026 b
Is HD 149026 b habitable?
HD 149026 b is not known to orbit within the habitable zone of HD 149026, and as a hot Jupiter it is an unlikely candidate for life as we know it.
How far away is HD 149026 b?
HD 149026 b is about 247 light-years from Earth in the constellation Hercules. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 4,354,240 years to get there.
How big is HD 149026 b compared to Earth?
HD 149026 b has 8.29 times the radius of Earth and about 121 times its mass.
How long is a year on HD 149026 b?
One orbit around HD 149026 takes 2.9 Earth days — short enough that 127 of its years would fit into one Earth year.
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