HD 126105 b
HD 126105 b is a cold gas giant orbiting the K1 III star HD 126105 in the constellation Libra. It lies about 270 light-years from Earth and was discovered in 2026 using the radial velocity method.
Is HD 126105 b in the Habitable Zone?
HD 126105 b orbits inside the inner edge of the habitable zone of HD 126105. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of HD 126105: 2.363–5.743 AU (conservative: 2.994–5.445 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 126105 b — one full orbit around HD 126105 — lasts 524.0 Earth days, longer than an Earth year. It orbits at an average distance of 1.360 AU. Its orbit is mildly elliptical (eccentricity 0.10).
How Was HD 126105 b Discovered?
HD 126105 b was discovered in 2026 using the radial velocity method, with observations from Multiple Facilities.
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 126105 b?
HD 126105 b is 270.3 light-years (82.9 parsecs) from Earth. Light arriving here tonight left the planet around the year 1756. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 4,757,280 years to make the journey.
The Host Star: HD 126105
HD 126105
- Spectral type
- K1 III
- Surface temperature
- 4,875 K (Sun: 5,772 K)
- Mass
- 1.20 M☉
- Radius
- 4.21 R☉
- Luminosity
- 8.9999 L☉
- Age
- 4.9 billion years (Sun: 4.6)
Planetary System
HD 126105 b is the only planet known to orbit HD 126105 so far.
HD 126105 b — Complete Data
| Mass (best estimate) | 530.77 Earth masses |
|---|---|
| Orbital period | 524.00 days |
| Orbital distance | 1.360 AU |
| Eccentricity | 0.103 |
| Distance from Earth | 270.3 light-years (82.9 parsecs) |
| Constellation | Libra |
| Discovery method | Radial Velocity |
| Discovery facility | Multiple Facilities |
| Discovery year | 2026 |
Data: NASA Exoplanet Archive, last updated 2026-07-02. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HD 126105 b
Is HD 126105 b habitable?
No — HD 126105 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is HD 126105 b?
HD 126105 b is about 270 light-years from Earth in the constellation Libra. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 4,757,280 years to get there.
How long is a year on HD 126105 b?
One orbit around HD 126105 takes 524.0 Earth days.
Explore HD 126105 b in the app
Browse, filter and compare 6,000+ exoplanets on iPhone, iPad and Apple Watch — with habitable-zone views, widgets and offline data.
