GJ 2126 b
GJ 2126 b is a cold gas giant orbiting the M0 V star GJ 2126 in the constellation Scorpius. It lies about 124 light-years from Earth and was discovered in 2025 using the radial velocity method. It orbits within the habitable zone of its star — the region where liquid water could exist on a planet's surface.
Is GJ 2126 b in the Habitable Zone?
GJ 2126 b orbits inside the conservative habitable zone of GJ 2126 — the region where a rocky planet could sustain liquid water on its surface. This makes it one of the most interesting known exoplanets in the search for life.
Habitable zone of GJ 2126: 0.305–0.767 AU (conservative: 0.387–0.727 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 GJ 2126 b — one full orbit around GJ 2126 — lasts 272.7 Earth days, between the years of Mercury (88 days) and Earth (365 days). It orbits at an average distance of 0.710 AU — comparable to the inner Solar System. Its orbit is highly elliptical (eccentricity 0.85), swinging dramatically closer to and farther from its star.
How Was GJ 2126 b Discovered?
GJ 2126 b was discovered in 2025 using the radial velocity method, with observations from La Silla 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 2126 b?
GJ 2126 b is 124.4 light-years (38.1 parsecs) from Earth. Light arriving here tonight left the planet around the year 1902. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 2,189,440 years to make the journey.
The Host Star: GJ 2126
GJ 2126
- Spectral type
- M0 V
- Surface temperature
- 4,159 K (Sun: 5,772 K)
- Mass
- 0.65 M☉
- Radius
- 0.73 R☉
- Luminosity
- 0.1428 L☉
Planetary System
GJ 2126 b is the only planet known to orbit GJ 2126 so far.
GJ 2126 b — Complete Data
| Mass (best estimate) | 413.18 Earth masses |
|---|---|
| Orbital period | 272.70 days |
| Orbital distance | 0.710 AU |
| Eccentricity | 0.850 |
| Distance from Earth | 124.4 light-years (38.1 parsecs) |
| Constellation | Scorpius |
| Discovery method | Radial Velocity |
| Discovery facility | La Silla Observatory |
| Discovery year | 2025 |
Data: NASA Exoplanet Archive, last updated 2025-03-03. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About GJ 2126 b
Is GJ 2126 b habitable?
GJ 2126 b orbits within the habitable zone of GJ 2126, the region where liquid water could exist on a planet's surface. It sits in the conservative habitable zone — the most promising region for habitability. Whether it is actually habitable depends on its atmosphere and composition, which remain unknown.
How far away is GJ 2126 b?
GJ 2126 b is about 124 light-years from Earth in the constellation Scorpius. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 2,189,440 years to get there.
How long is a year on GJ 2126 b?
One orbit around GJ 2126 takes 272.7 Earth days.
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