HIP 65891 b
The parameters of this planet are disputed or ambiguous in the scientific literature.
HIP 65891 b is a cold gas giant orbiting the K0 III star HIP 65891 in the constellation Centaurus. It lies about 490 light-years from Earth and was discovered in 2015 using the radial velocity method.
Is HIP 65891 b in the Habitable Zone?
HIP 65891 b orbits inside the inner edge of the habitable zone of HIP 65891. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of HIP 65891: 5.238–12.664 AU (conservative: 6.634–12.006 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 HIP 65891 b — one full orbit around HIP 65891 — lasts 1,089.6 Earth days, longer than an Earth year. It orbits at an average distance of 2.820 AU. Its orbit is mildly elliptical (eccentricity 0.09).
How Was HIP 65891 b Discovered?
HIP 65891 b was discovered in 2015 using the radial velocity method, with observations from Multiple Observatories.
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 HIP 65891 b?
HIP 65891 b is 490.2 light-years (150.3 parsecs) from Earth. Light arriving here tonight left the planet around the year 1536. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 8,627,520 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. HIP 65891 b scores 0.22, ranking #3,699 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: HIP 65891
HIP 65891
- Spectral type
- K0 III
- Surface temperature
- 5,000 K (Sun: 5,772 K)
- Mass
- 2.50 M☉
- Radius
- 8.93 R☉
Planetary System
HIP 65891 b is the only planet known to orbit HIP 65891 so far.
HIP 65891 b — Complete Data
| Mass | 1,938.75 Earth masses (6.100 Jupiter masses) |
|---|---|
| Orbital period | 1,089.60 days |
| Orbital distance | 2.820 AU |
| Eccentricity | 0.090 |
| Earth Similarity Index | 0.22 |
| Distance from Earth | 490.2 light-years (150.3 parsecs) |
| Constellation | Centaurus |
| Discovery method | Radial Velocity |
| Discovery facility | Multiple Observatories |
| Discovery year | 2015 |
Data: NASA Exoplanet Archive, last updated 2026-06-04. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HIP 65891 b
Is HIP 65891 b habitable?
No — HIP 65891 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is HIP 65891 b?
HIP 65891 b is about 490 light-years from Earth in the constellation Centaurus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 8,627,520 years to get there.
How long is a year on HIP 65891 b?
One orbit around HIP 65891 takes 1,089.6 Earth days.
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