HD 38529 b
HD 38529 b is a cold gas giant orbiting HD 38529 in the constellation Orion. It lies about 138 light-years from Earth and was discovered in 2000 using the radial velocity method.
Is HD 38529 b in the Habitable Zone?
The position of HD 38529 b relative to the habitable zone of HD 38529 cannot be precisely determined from the available orbital data.
Orbit and Year Length
A year on HD 38529 b — one full orbit around HD 38529 — lasts 14.3 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.115 AU — closer to its star than Mercury is to the Sun. Its orbit is mildly elliptical (eccentricity 0.26).
How Was HD 38529 b Discovered?
HD 38529 b was discovered in 2000 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 HD 38529 b?
HD 38529 b is 138.1 light-years (42.4 parsecs) from Earth. Light arriving here tonight left the planet around the year 1888. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 2,430,560 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 38529 b scores 0.07, ranking #5,037 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: HD 38529
HD 38529 b belongs to a system of 2 stars; it orbits HD 38529.
HD 38529
- Mass
- 0.98 M☉
The HD 38529 Planetary System
HD 38529 b is one of 2 known planets in the HD 38529 system. Its siblings:
- HD 38529 c (Cold Gas Giant)
HD 38529 b — Complete Data
| Mass (best estimate) | 206.59 Earth masses |
|---|---|
| Orbital period | 14.31 days |
| Orbital distance | 0.115 AU |
| Eccentricity | 0.256 |
| Earth Similarity Index | 0.07 |
| Distance from Earth | 138.1 light-years (42.4 parsecs) |
| Constellation | Orion |
| Discovery method | Radial Velocity |
| Discovery facility | Multiple Observatories |
| Discovery year | 2000 |
Data: NASA Exoplanet Archive, last updated 2023-06-14. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HD 38529 b
Is HD 38529 b habitable?
HD 38529 b is not known to orbit within the habitable zone of HD 38529, and as a cold gas giant it is an unlikely candidate for life as we know it.
How far away is HD 38529 b?
HD 38529 b is about 138 light-years from Earth in the constellation Orion. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 2,430,560 years to get there.
How long is a year on HD 38529 b?
One orbit around HD 38529 takes 14.3 Earth days — short enough that 26 of its years would fit into one Earth year.
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