HD 66428 c
HD 66428 c is a cold gas giant orbiting HD 66428 in the constellation Monoceros. It lies about 174 light-years from Earth and was discovered in 2021 using the radial velocity method.
Is HD 66428 c in the Habitable Zone?
The position of HD 66428 c 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 c — one full orbit around HD 66428 — lasts 10,478.8 Earth days, longer than Jupiter's 12-year orbit. It orbits at an average distance of 9.408 AU. Its orbit is mildly elliptical (eccentricity 0.21).
How Was HD 66428 c Discovered?
HD 66428 c was discovered in 2021 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 66428 c?
HD 66428 c 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 c scores 0.08, ranking #4,633 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 c is one of 2 known planets in the HD 66428 system. Its siblings:
- HD 66428 b (Cold Gas Giant)
HD 66428 c — Complete Data
| Mass | 560.65 Earth masses (1.764 Jupiter masses) |
|---|---|
| Orbital period | 10,478.84 days |
| Orbital distance | 9.408 AU |
| Eccentricity | 0.207 |
| Earth Similarity Index | 0.08 |
| Distance from Earth | 173.8 light-years (53.3 parsecs) |
| Constellation | Monoceros |
| Discovery method | Radial Velocity |
| Discovery facility | Multiple Observatories |
| Discovery year | 2021 |
Data: NASA Exoplanet Archive, last updated 2023-06-12. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HD 66428 c
Is HD 66428 c habitable?
HD 66428 c 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 c?
HD 66428 c 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 c?
One orbit around HD 66428 takes 10,478.8 Earth days.
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