HD 31527 c
HD 31527 c is a Neptune-like planet orbiting the G2 V star HD 31527 in the constellation Lepus. It lies about 125 light-years from Earth and was discovered in 2019 using the radial velocity method.
Is HD 31527 c in the Habitable Zone?
HD 31527 c orbits inside the inner edge of the habitable zone of HD 31527. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of HD 31527: 0.816–1.917 AU (conservative: 1.034–1.817 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 31527 c — one full orbit around HD 31527 — lasts 51.2 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.266 AU — closer to its star than Mercury is to the Sun. Its orbit is nearly circular (eccentricity 0.040).
How Was HD 31527 c Discovered?
HD 31527 c was discovered in 2019 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 31527 c?
HD 31527 c is 125.4 light-years (38.4 parsecs) from Earth. Light arriving here tonight left the planet around the year 1901. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 2,207,040 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 31527 c scores 0.25, ranking #3,169 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: HD 31527
HD 31527
- Spectral type
- G2 V
- Surface temperature
- 5,898 K (Sun: 5,772 K)
- Mass
- 0.96 M☉
- Luminosity
- 1.2000 L☉
The HD 31527 Planetary System
HD 31527 c is one of 3 known planets in the HD 31527 system. Its siblings:
- HD 31527 b (Neptune-like)
- HD 31527 d (Neptune-like)
HD 31527 c — Complete Data
| Mass (best estimate) | 14.16 Earth masses |
|---|---|
| Orbital period | 51.21 days |
| Orbital distance | 0.266 AU |
| Eccentricity | 0.040 |
| Earth Similarity Index | 0.25 |
| Distance from Earth | 125.4 light-years (38.4 parsecs) |
| Constellation | Lepus |
| Discovery method | Radial Velocity |
| Discovery facility | La Silla Observatory |
| Discovery year | 2019 |
Data: NASA Exoplanet Archive, last updated 2019-02-05. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HD 31527 c
Is HD 31527 c habitable?
No — HD 31527 c orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is HD 31527 c?
HD 31527 c is about 125 light-years from Earth in the constellation Lepus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 2,207,040 years to get there.
How long is a year on HD 31527 c?
One orbit around HD 31527 takes 51.2 Earth days.
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