HD 188015 b
HD 188015 b is a cold gas giant orbiting HD 188015 in the constellation Vulpecula. It lies about 165 light-years from Earth and was discovered in 2004 using the radial velocity method.
Is HD 188015 b in the Habitable Zone?
The position of HD 188015 b relative to the habitable zone of HD 188015 cannot be precisely determined from the available orbital data.
Orbit and Year Length
A year on HD 188015 b — one full orbit around HD 188015 — lasts 461.2 Earth days, longer than an Earth year. It orbits at an average distance of 1.203 AU. Its orbit is mildly elliptical (eccentricity 0.14).
How Was HD 188015 b Discovered?
HD 188015 b was discovered in 2004 using the radial velocity method, with observations from W. M. Keck 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 188015 b?
HD 188015 b is 165.3 light-years (50.7 parsecs) from Earth. Light arriving here tonight left the planet around the year 1861. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 2,909,280 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 188015 b scores 0.38, ranking #548 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: HD 188015
HD 188015 b belongs to a system of 2 stars; it orbits HD 188015.
HD 188015
- Surface temperature
- 5,746 K (Sun: 5,772 K)
- Mass
- 1.09 M☉
Planetary System
HD 188015 b is the only planet known to orbit HD 188015 so far.
HD 188015 b — Complete Data
| Mass (best estimate) | 476.72 Earth masses |
|---|---|
| Orbital period | 461.20 days |
| Orbital distance | 1.203 AU |
| Eccentricity | 0.137 |
| Earth Similarity Index | 0.38 |
| Distance from Earth | 165.3 light-years (50.7 parsecs) |
| Constellation | Vulpecula |
| Discovery method | Radial Velocity |
| Discovery facility | W. M. Keck Observatory |
| Discovery year | 2004 |
Data: NASA Exoplanet Archive, last updated 2014-07-23. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HD 188015 b
Is HD 188015 b habitable?
HD 188015 b is not known to orbit within the habitable zone of HD 188015, and as a cold gas giant it is an unlikely candidate for life as we know it.
How far away is HD 188015 b?
HD 188015 b is about 165 light-years from Earth in the constellation Vulpecula. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 2,909,280 years to get there.
How long is a year on HD 188015 b?
One orbit around HD 188015 takes 461.2 Earth days.
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