GJ 422 b
GJ 422 b is a Neptune-like planet orbiting GJ 422 in the constellation Carina. It lies about 41 light-years from Earth and was discovered in 2014 using the radial velocity method.
Is GJ 422 b in the Habitable Zone?
The position of GJ 422 b relative to the habitable zone of GJ 422 cannot be precisely determined from the available orbital data.
Orbit and Year Length
A year on GJ 422 b — one full orbit around GJ 422 — lasts 20.1 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.111 AU — closer to its star than Mercury is to the Sun. Its orbit is mildly elliptical (eccentricity 0.11).
How Was GJ 422 b Discovered?
GJ 422 b was discovered in 2014 using the radial velocity method, with observations from Multiple Observatories.
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 422 b?
GJ 422 b is 41.3 light-years (12.7 parsecs) from Earth. Light arriving here tonight left the planet around the year 1985. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 726,880 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. GJ 422 b scores 0.62, ranking #119 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: GJ 422
GJ 422
- Mass
- 0.35 M☉
Planetary System
GJ 422 b is the only planet known to orbit GJ 422 so far.
GJ 422 b — Complete Data
| Mass (best estimate) | 11.07 Earth masses |
|---|---|
| Orbital period | 20.13 days |
| Orbital distance | 0.111 AU |
| Eccentricity | 0.110 |
| Earth Similarity Index | 0.62 |
| Distance from Earth | 41.3 light-years (12.7 parsecs) |
| Constellation | Carina |
| Discovery method | Radial Velocity |
| Discovery facility | Multiple Observatories |
| Discovery year | 2014 |
Data: NASA Exoplanet Archive, last updated 2020-02-06. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About GJ 422 b
Is GJ 422 b habitable?
GJ 422 b is not known to orbit within the habitable zone of GJ 422, and as a Neptune-like planet it is an unlikely candidate for life as we know it.
How far away is GJ 422 b?
GJ 422 b is about 41 light-years from Earth in the constellation Carina. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 726,880 years to get there.
How long is a year on GJ 422 b?
One orbit around GJ 422 takes 20.1 Earth days — short enough that 18 of its years would fit into one Earth year.
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