GJ 687 b
GJ 687 b is a Neptune-like planet orbiting GJ 687 in the constellation Draco. It lies about 15 light-years from Earth and was discovered in 2014 using the radial velocity method.
Is GJ 687 b in the Habitable Zone?
The position of GJ 687 b relative to the habitable zone of GJ 687 cannot be precisely determined from the available orbital data.
Orbit and Year Length
A year on GJ 687 b — one full orbit around GJ 687 — lasts 38.1 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.163 AU — closer to its star than Mercury is to the Sun. Its orbit is mildly elliptical (eccentricity 0.17).
How Was GJ 687 b Discovered?
GJ 687 b was discovered in 2014 using the radial velocity method, with observations from Lick 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 GJ 687 b?
GJ 687 b is 14.8 light-years (4.5 parsecs) from Earth. Light arriving here tonight left the planet around the year 2012. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 260,480 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. GJ 687 b scores 0.55, ranking #191 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: GJ 687
GJ 687
- Mass
- 0.40 M☉
The GJ 687 Planetary System
GJ 687 b is one of 2 known planets in the GJ 687 system. Its siblings:
- GJ 687 c (Neptune-like)
GJ 687 b — Complete Data
| Mass (best estimate) | 17.20 Earth masses |
|---|---|
| Orbital period | 38.14 days |
| Orbital distance | 0.163 AU |
| Eccentricity | 0.170 |
| Earth Similarity Index | 0.55 |
| Distance from Earth | 14.8 light-years (4.5 parsecs) |
| Constellation | Draco |
| Discovery method | Radial Velocity |
| Discovery facility | Lick Observatory |
| Discovery year | 2014 |
Data: NASA Exoplanet Archive, last updated 2020-09-08. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About GJ 687 b
Is GJ 687 b habitable?
GJ 687 b is not known to orbit within the habitable zone of GJ 687, and as a Neptune-like planet it is an unlikely candidate for life as we know it.
How far away is GJ 687 b?
GJ 687 b is about 15 light-years from Earth in the constellation Draco. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 260,480 years to get there.
How long is a year on GJ 687 b?
One orbit around GJ 687 takes 38.1 Earth days.
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