HD 21411 b
HD 21411 b is a cold gas giant orbiting the G8 V star HD 21411 in the constellation Fornax. It lies about 95 light-years from Earth and was discovered in 2019 using the radial velocity method.
Is HD 21411 b in the Habitable Zone?
The position of HD 21411 b relative to the habitable zone of HD 21411 cannot be precisely determined from the available orbital data.
Orbit and Year Length
A year on HD 21411 b — one full orbit around HD 21411 — lasts 84.3 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.362 AU — closer to its star than Mercury is to the Sun. Its orbit is highly elliptical (eccentricity 0.40), swinging dramatically closer to and farther from its star.
How Was HD 21411 b Discovered?
HD 21411 b was discovered in 2019 using the radial velocity method, with observations from Las Campanas 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 21411 b?
HD 21411 b is 95.0 light-years (29.1 parsecs) from Earth. Light arriving here tonight left the planet around the year 1931. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 1,672,000 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 21411 b scores 0.27, ranking #2,573 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: HD 21411
HD 21411
- Spectral type
- G8 V
- Surface temperature
- 5,605 K (Sun: 5,772 K)
- Mass
- 0.89 M☉
Planetary System
HD 21411 b is the only planet known to orbit HD 21411 so far.
HD 21411 b — Complete Data
| Mass (best estimate) | 65.90 Earth masses |
|---|---|
| Orbital period | 84.29 days |
| Orbital distance | 0.362 AU |
| Eccentricity | 0.400 |
| Earth Similarity Index | 0.27 |
| Distance from Earth | 95.0 light-years (29.1 parsecs) |
| Constellation | Fornax |
| Discovery method | Radial Velocity |
| Discovery facility | Las Campanas Observatory |
| Discovery year | 2019 |
Data: NASA Exoplanet Archive, last updated 2019-05-20. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HD 21411 b
Is HD 21411 b habitable?
HD 21411 b is not known to orbit within the habitable zone of HD 21411, and as a cold gas giant it is an unlikely candidate for life as we know it.
How far away is HD 21411 b?
HD 21411 b is about 95 light-years from Earth in the constellation Fornax. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 1,672,000 years to get there.
How long is a year on HD 21411 b?
One orbit around HD 21411 takes 84.3 Earth days.
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