HD 74156 b
HD 74156 b is a cold gas giant orbiting HD 74156 in the constellation Hydra. It lies about 188 light-years from Earth and was discovered in 2003 using the radial velocity method.
Is HD 74156 b in the Habitable Zone?
The position of HD 74156 b relative to the habitable zone of HD 74156 cannot be precisely determined from the available orbital data.
Orbit and Year Length
A year on HD 74156 b — one full orbit around HD 74156 — lasts 51.6 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.280 AU — closer to its star than Mercury is to the Sun. Its orbit is highly elliptical (eccentricity 0.64), swinging dramatically closer to and farther from its star.
How Was HD 74156 b Discovered?
HD 74156 b was discovered in 2003 using the radial velocity method, with observations from Haute-Provence 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 74156 b?
HD 74156 b is 187.9 light-years (57.6 parsecs) from Earth. Light arriving here tonight left the planet around the year 1839. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 3,307,040 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 74156 b scores 0.09, ranking #4,508 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: HD 74156
HD 74156
- Mass
- 1.10 M☉
The HD 74156 Planetary System
HD 74156 b is one of 2 known planets in the HD 74156 system. Its siblings:
- HD 74156 c (Cold Gas Giant)
HD 74156 b — Complete Data
| Mass (best estimate) | 532.36 Earth masses |
|---|---|
| Orbital period | 51.64 days |
| Orbital distance | 0.280 AU |
| Eccentricity | 0.636 |
| Earth Similarity Index | 0.09 |
| Distance from Earth | 187.9 light-years (57.6 parsecs) |
| Constellation | Hydra |
| Discovery method | Radial Velocity |
| Discovery facility | Haute-Provence Observatory |
| Discovery year | 2003 |
Data: NASA Exoplanet Archive, last updated 2023-06-14. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HD 74156 b
Is HD 74156 b habitable?
HD 74156 b is not known to orbit within the habitable zone of HD 74156, and as a cold gas giant it is an unlikely candidate for life as we know it.
How far away is HD 74156 b?
HD 74156 b is about 188 light-years from Earth in the constellation Hydra. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 3,307,040 years to get there.
How long is a year on HD 74156 b?
One orbit around HD 74156 takes 51.6 Earth days.
Explore HD 74156 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.
