HD 11964 c
HD 11964 c is a Neptune-like planet orbiting HD 11964 in the constellation Cetus. It lies about 109 light-years from Earth and was discovered in 2008 using the radial velocity method.
Is HD 11964 c in the Habitable Zone?
HD 11964 c orbits inside the inner edge of the habitable zone of HD 11964. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of HD 11964: 1.308–3.128 AU (conservative: 1.657–2.965 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 11964 c — one full orbit around HD 11964 — lasts 37.9 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.229 AU — closer to its star than Mercury is to the Sun. Its orbit is highly elliptical (eccentricity 0.30), swinging dramatically closer to and farther from its star.
How Was HD 11964 c Discovered?
HD 11964 c was discovered in 2008 using the radial velocity method, with observations from W. M. Keck 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 11964 c?
HD 11964 c is 109.4 light-years (33.5 parsecs) from Earth. Light arriving here tonight left the planet around the year 1917. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 1,925,440 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 11964 c scores 0.16, ranking #4,133 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: HD 11964
HD 11964 c belongs to a system of 2 stars; it orbits HD 11964.
HD 11964
- Surface temperature
- 5,303 K (Sun: 5,772 K)
- Mass
- 0.91 M☉
- Radius
- 2.01 R☉
- Luminosity
- 2.8777 L☉
The HD 11964 Planetary System
HD 11964 c is one of 2 known planets in the HD 11964 system. Its siblings:
- HD 11964 b (Cold Gas Giant)
HD 11964 c — Complete Data
| Mass (best estimate) | 25.00 Earth masses |
|---|---|
| Orbital period | 37.91 days |
| Orbital distance | 0.229 AU |
| Eccentricity | 0.300 |
| Earth Similarity Index | 0.16 |
| Distance from Earth | 109.4 light-years (33.5 parsecs) |
| Constellation | Cetus |
| Discovery method | Radial Velocity |
| Discovery facility | W. M. Keck Observatory |
| Discovery year | 2008 |
Data: NASA Exoplanet Archive, last updated 2019-01-28. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HD 11964 c
Is HD 11964 c habitable?
No — HD 11964 c orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is HD 11964 c?
HD 11964 c is about 109 light-years from Earth in the constellation Cetus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 1,925,440 years to get there.
How long is a year on HD 11964 c?
One orbit around HD 11964 takes 37.9 Earth days.
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