HD 5388 b
The parameters of this planet are disputed or ambiguous in the scientific literature.
HD 5388 b is a cold gas giant orbiting the F6 V star HD 5388 in the constellation Phoenix. It lies about 173 light-years from Earth and was discovered in 2010 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 HD 5388 b in the Habitable Zone?
HD 5388 b orbits within the optimistic habitable zone of HD 5388 — the broader region where liquid water might be possible under favorable atmospheric conditions.
Habitable zone of HD 5388: 1.650–3.842 AU (conservative: 2.089–3.642 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 5388 b — one full orbit around HD 5388 — lasts 772.5 Earth days, longer than an Earth year. It orbits at an average distance of 1.757 AU. Its orbit is highly elliptical (eccentricity 0.41), swinging dramatically closer to and farther from its star.
How Was HD 5388 b Discovered?
HD 5388 b was discovered in 2010 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 HD 5388 b?
HD 5388 b is 173.1 light-years (53.1 parsecs) from Earth. Light arriving here tonight left the planet around the year 1853. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 3,046,560 years to make the journey.
The Host Star: HD 5388
HD 5388
- Spectral type
- F6 V
- Surface temperature
- 6,297 K (Sun: 5,772 K)
- Mass
- 1.21 M☉
- Radius
- 1.91 R☉
Planetary System
HD 5388 b is the only planet known to orbit HD 5388 so far.
HD 5388 b — Complete Data
| Mass | 1,017.05 Earth masses (3.200 Jupiter masses) |
|---|---|
| Orbital period | 772.50 days |
| Orbital distance | 1.757 AU |
| Eccentricity | 0.410 |
| Distance from Earth | 173.1 light-years (53.1 parsecs) |
| Constellation | Phoenix |
| Discovery method | Radial Velocity |
| Discovery facility | La Silla Observatory |
| Discovery year | 2010 |
Data: NASA Exoplanet Archive, last updated 2026-06-04. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HD 5388 b
Is HD 5388 b habitable?
HD 5388 b orbits within the habitable zone of HD 5388, the region where liquid water could exist on a planet's surface. Whether it is actually habitable depends on its atmosphere and composition, which remain unknown.
How far away is HD 5388 b?
HD 5388 b is about 173 light-years from Earth in the constellation Phoenix. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 3,046,560 years to get there.
How long is a year on HD 5388 b?
One orbit around HD 5388 takes 772.5 Earth days.
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