HD 108863 b
HD 108863 b is a cold gas giant orbiting HD 108863 in the constellation Coma Berenices. It lies about 537 light-years from Earth and was discovered in 2011 using the radial velocity method.
Is HD 108863 b in the Habitable Zone?
HD 108863 b orbits inside the inner edge of the habitable zone of HD 108863. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of HD 108863: 3.223–7.830 AU (conservative: 4.082–7.424 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 108863 b — one full orbit around HD 108863 — lasts 437.7 Earth days, longer than an Earth year. It orbits at an average distance of 1.320 AU. Its orbit is nearly circular (eccentricity 0.032).
How Was HD 108863 b Discovered?
HD 108863 b was discovered in 2011 using the radial velocity method, with observations from W. M. Keck 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 108863 b?
HD 108863 b is 537.3 light-years (164.7 parsecs) from Earth. Light arriving here tonight left the planet around the year 1489. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 9,456,480 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. HD 108863 b scores 0.16, ranking #4,123 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: HD 108863
HD 108863
- Surface temperature
- 4,878 K (Sun: 5,772 K)
- Mass
- 1.59 M☉
- Radius
- 5.74 R☉
Planetary System
HD 108863 b is the only planet known to orbit HD 108863 so far.
HD 108863 b — Complete Data
| Mass (best estimate) | 767.24 Earth masses |
|---|---|
| Orbital period | 437.70 days |
| Orbital distance | 1.320 AU |
| Eccentricity | 0.032 |
| Earth Similarity Index | 0.16 |
| Distance from Earth | 537.3 light-years (164.7 parsecs) |
| Constellation | Coma Berenices |
| Discovery method | Radial Velocity |
| Discovery facility | W. M. Keck Observatory |
| Discovery year | 2011 |
Data: NASA Exoplanet Archive, last updated 2018-12-03. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HD 108863 b
Is HD 108863 b habitable?
No — HD 108863 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is HD 108863 b?
HD 108863 b is about 537 light-years from Earth in the constellation Coma Berenices. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 9,456,480 years to get there.
How long is a year on HD 108863 b?
One orbit around HD 108863 takes 437.7 Earth days.
Explore HD 108863 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.
