HD 87816 b
HD 87816 b is a cold gas giant orbiting the K0 III star HD 87816 in the constellation Vela. It lies about 435 light-years from Earth and was discovered in 2025 using the radial velocity method.
Is HD 87816 b in the Habitable Zone?
HD 87816 b orbits inside the inner edge of the habitable zone of HD 87816. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of HD 87816: 5.269–12.744 AU (conservative: 6.674–12.083 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 87816 b — one full orbit around HD 87816 — lasts 484.2 Earth days, longer than an Earth year. It orbits at an average distance of 1.618 AU. Its orbit is highly elliptical (eccentricity 0.78), swinging dramatically closer to and farther from its star.
How Was HD 87816 b Discovered?
HD 87816 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 87816 b?
HD 87816 b is 434.5 light-years (133.2 parsecs) from Earth. Light arriving here tonight left the planet around the year 1592. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 7,647,200 years to make the journey.
The Host Star: HD 87816
HD 87816
- Spectral type
- K0 III
- Surface temperature
- 4,989 K (Sun: 5,772 K)
- Mass
- 2.41 M☉
- Radius
- 9.00 R☉
- Luminosity
- 45.2002 L☉
The HD 87816 Planetary System
HD 87816 b is one of 2 known planets in the HD 87816 system. Its siblings:
- HD 87816 c (Cold Gas Giant)
HD 87816 b — Complete Data
| Mass (best estimate) | 2,142.16 Earth masses |
|---|---|
| Orbital period | 484.17 days |
| Orbital distance | 1.618 AU |
| Eccentricity | 0.780 |
| Distance from Earth | 434.5 light-years (133.2 parsecs) |
| Constellation | Vela |
| 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 87816 b
Is HD 87816 b habitable?
No — HD 87816 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is HD 87816 b?
HD 87816 b is about 435 light-years from Earth in the constellation Vela. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 7,647,200 years to get there.
How long is a year on HD 87816 b?
One orbit around HD 87816 takes 484.2 Earth days.