HD 28471 b
HD 28471 b is a super-Earth orbiting the G5 V star HD 28471 in the constellation Reticulum. It lies about 142 light-years from Earth and was discovered in 2025 using the radial velocity method.
Is HD 28471 b in the Habitable Zone?
HD 28471 b orbits inside the inner edge of the habitable zone of HD 28471. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of HD 28471: 0.808–1.904 AU (conservative: 1.023–1.805 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Temperature on HD 28471 b
The equilibrium temperature of HD 28471 b is about 1,377 K (1,104 °C) — hot enough to melt many metals. This estimate ignores any atmosphere, which could change surface temperatures dramatically — Earth's greenhouse effect adds about 33 °C.
Orbit and Year Length
A year on HD 28471 b — one full orbit around HD 28471 — lasts 3.16 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.042 AU — closer to its star than Mercury is to the Sun. Its orbit is mildly elliptical (eccentricity 0.20).
How Was HD 28471 b Discovered?
HD 28471 b was discovered in 2025 using the radial velocity method, with observations from La Silla 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 28471 b?
HD 28471 b is 142.4 light-years (43.6 parsecs) from Earth. Light arriving here tonight left the planet around the year 1884. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 2,506,240 years to make the journey.
The Host Star: HD 28471
HD 28471
- Spectral type
- G5 V
- Surface temperature
- 5,766 K (Sun: 5,772 K)
- Mass
- 0.98 M☉
- Radius
- 1.08 R☉
- Age
- 6.6 billion years (Sun: 4.6)
The HD 28471 Planetary System
HD 28471 b is one of 3 known planets in the HD 28471 system. Its siblings:
- HD 28471 c (Super Earth)
- HD 28471 d (Super Earth)
HD 28471 b — Complete Data
| Mass (best estimate) | 3.72 Earth masses |
|---|---|
| Orbital period | 3.16 days |
| Orbital distance | 0.042 AU |
| Eccentricity | 0.195 |
| Equilibrium temperature | 1,377 K (1,104 °C) |
| Distance from Earth | 142.4 light-years (43.6 parsecs) |
| Constellation | Reticulum |
| Discovery method | Radial Velocity |
| Discovery facility | La Silla Observatory |
| Discovery year | 2025 |
Data: NASA Exoplanet Archive, last updated 2025-09-17. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HD 28471 b
Is HD 28471 b habitable?
No — HD 28471 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is HD 28471 b?
HD 28471 b is about 142 light-years from Earth in the constellation Reticulum. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 2,506,240 years to get there.
How long is a year on HD 28471 b?
One orbit around HD 28471 takes 3.2 Earth days — short enough that 115 of its years would fit into one Earth year.
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