HD 102888 b
HD 102888 b is a cold gas giant orbiting the G8 III star HD 102888 in the constellation Hydra. It lies about 413 light-years from Earth and was discovered in 2025 using the radial velocity method.
Is HD 102888 b in the Habitable Zone?
HD 102888 b orbits inside the inner edge of the habitable zone of HD 102888. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of HD 102888: 5.035–12.179 AU (conservative: 6.378–11.547 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 102888 b — one full orbit around HD 102888 — lasts 252.1 Earth days, between the years of Mercury (88 days) and Earth (365 days). It orbits at an average distance of 1.050 AU — comparable to the inner Solar System. Its orbit is mildly elliptical (eccentricity 0.11).
How Was HD 102888 b Discovered?
HD 102888 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 HD 102888 b?
HD 102888 b is 412.5 light-years (126.5 parsecs) from Earth. Light arriving here tonight left the planet around the year 1614. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 7,260,000 years to make the journey.
The Host Star: HD 102888
HD 102888
- Spectral type
- G8 III
- Surface temperature
- 4,990 K (Sun: 5,772 K)
- Mass
- 2.42 M☉
- Radius
- 8.60 R☉
- Luminosity
- 41.2895 L☉
Planetary System
HD 102888 b is the only planet known to orbit HD 102888 so far.
HD 102888 b — Complete Data
| Mass (best estimate) | 1,808.44 Earth masses |
|---|---|
| Orbital period | 252.06 days |
| Orbital distance | 1.050 AU |
| Eccentricity | 0.110 |
| Distance from Earth | 412.5 light-years (126.5 parsecs) |
| Constellation | Hydra |
| Discovery method | Radial Velocity |
| Discovery facility | La Silla Observatory |
| Discovery year | 2025 |
Data: NASA Exoplanet Archive, last updated 2025-05-27. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HD 102888 b
Is HD 102888 b habitable?
No — HD 102888 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is HD 102888 b?
HD 102888 b is about 413 light-years from Earth in the constellation Hydra. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 7,260,000 years to get there.
How long is a year on HD 102888 b?
One orbit around HD 102888 takes 252.1 Earth days.
Explore HD 102888 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.
