HD 25723 b
HD 25723 b is a cold gas giant orbiting the K1 III star HD 25723 in the constellation Eridanus. It lies about 375 light-years from Earth and was discovered in 2020 using the radial velocity method.
Is HD 25723 b in the Habitable Zone?
HD 25723 b orbits inside the inner edge of the habitable zone of HD 25723. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of HD 25723: 7.425–18.127 AU (conservative: 9.405–17.186 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
See the full interactive habitable-zone view in the Exoplanet Explorer app ›
Orbit and Year Length
A year on HD 25723 b — one full orbit around HD 25723 — lasts 457.0 Earth days, longer than an Earth year. It orbits at an average distance of 1.490 AU. Its orbit is nearly circular (eccentricity 0.040).
How Was HD 25723 b Discovered?
HD 25723 b was discovered in 2020 using the radial velocity method, with observations from Lick 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 25723 b?
HD 25723 b is 374.5 light-years (114.8 parsecs) from Earth. Light arriving here tonight left the planet around the year 1652. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 6,591,200 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 25723 b scores 0.09, ranking #4,490 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: HD 25723
HD 25723
- Spectral type
- K1 III
- Surface temperature
- 4,766 K (Sun: 5,772 K)
- Mass
- 2.12 M☉
- Radius
- 13.76 R☉
- Luminosity
- 87.9893 L☉
- Age
- 1.0 billion years (Sun: 4.6)
Planetary System
HD 25723 b is the only planet known to orbit HD 25723 so far.
HD 25723 b — Complete Data
| Mass (best estimate) | 794.57 Earth masses |
|---|---|
| Orbital period | 457.01 days |
| Orbital distance | 1.490 AU |
| Eccentricity | 0.040 |
| Earth Similarity Index | 0.09 |
| Distance from Earth | 374.5 light-years (114.8 parsecs) |
| Constellation | Eridanus |
| Discovery method | Radial Velocity |
| Discovery facility | Lick Observatory |
| Discovery year | 2020 |
Data: NASA Exoplanet Archive, last updated 2021-10-25. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HD 25723 b
Is HD 25723 b habitable?
No — HD 25723 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is HD 25723 b?
HD 25723 b is about 375 light-years from Earth in the constellation Eridanus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 6,591,200 years to get there.
How long is a year on HD 25723 b?
One orbit around HD 25723 takes 457.0 Earth days.
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