HD 66428 b
HD 66428 b is a cold gas giant orbiting HD 66428 in the constellation Monoceros. It lies about 174 light-years from Earth and was discovered in 2005 using the radial velocity method.
Is HD 66428 b in the Habitable Zone?
The position of HD 66428 b relative to the habitable zone of HD 66428 cannot be precisely determined from the available orbital data.
Orbit and Year Length
A year on HD 66428 b — one full orbit around HD 66428 — lasts 2,269.8 Earth days, longer than an Earth year. It orbits at an average distance of 3.395 AU. Its orbit is highly elliptical (eccentricity 0.47), swinging dramatically closer to and farther from its star.
How Was HD 66428 b Discovered?
HD 66428 b was discovered in 2005 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 66428 b?
HD 66428 b is 173.8 light-years (53.3 parsecs) from Earth. Light arriving here tonight left the planet around the year 1853. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 3,058,880 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 66428 b scores 0.18, ranking #4,020 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: HD 66428
HD 66428
- Mass
- 1.01 M☉
The HD 66428 Planetary System
HD 66428 b is one of 2 known planets in the HD 66428 system. Its siblings:
- HD 66428 c (Cold Gas Giant)
HD 66428 b — Complete Data
| Mass | 3,478.95 Earth masses (10.946 Jupiter masses) |
|---|---|
| Orbital period | 2,269.82 days |
| Orbital distance | 3.395 AU |
| Eccentricity | 0.471 |
| Earth Similarity Index | 0.18 |
| Distance from Earth | 173.8 light-years (53.3 parsecs) |
| Constellation | Monoceros |
| Discovery method | Radial Velocity |
| Discovery facility | W. M. Keck Observatory |
| Discovery year | 2005 |
Data: NASA Exoplanet Archive, last updated 2023-06-12. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HD 66428 b
Is HD 66428 b habitable?
HD 66428 b is not known to orbit within the habitable zone of HD 66428, and as a cold gas giant it is an unlikely candidate for life as we know it.
How far away is HD 66428 b?
HD 66428 b is about 174 light-years from Earth in the constellation Monoceros. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 3,058,880 years to get there.
How long is a year on HD 66428 b?
One orbit around HD 66428 takes 2,269.8 Earth days.
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