HD 99706 c
HD 99706 c is a cold gas giant orbiting HD 99706 in the constellation Ursa Major. It lies about 478 light-years from Earth and was discovered in 2016 using the radial velocity method.
Is HD 99706 c in the Habitable Zone?
The position of HD 99706 c relative to the habitable zone of HD 99706 cannot be precisely determined from the available orbital data.
Habitable zone of HD 99706: 3.081–7.491 AU (conservative: 3.903–7.102 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 99706 c — one full orbit around HD 99706 — lasts 1,278.0 Earth days, longer than an Earth year. Its orbit is highly elliptical (eccentricity 0.41), swinging dramatically closer to and farther from its star.
How Was HD 99706 c Discovered?
HD 99706 c was discovered in 2016 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 99706 c?
HD 99706 c is 478.1 light-years (146.6 parsecs) from Earth. Light arriving here tonight left the planet around the year 1548. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 8,414,560 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 99706 c scores 0.30, ranking #1,249 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: HD 99706
HD 99706
- Surface temperature
- 4,862 K (Sun: 5,772 K)
- Mass
- 1.46 M☉
- Radius
- 5.52 R☉
The HD 99706 Planetary System
HD 99706 c is one of 2 known planets in the HD 99706 system. Its siblings:
- HD 99706 b (Cold Gas Giant)
HD 99706 c — Complete Data
| Mass (best estimate) | 1,808.45 Earth masses |
|---|---|
| Orbital period | 1,278.00 days |
| Eccentricity | 0.411 |
| Earth Similarity Index | 0.30 |
| Distance from Earth | 478.1 light-years (146.6 parsecs) |
| Constellation | Ursa Major |
| Discovery method | Radial Velocity |
| Discovery facility | W. M. Keck Observatory |
| Discovery year | 2016 |
Data: NASA Exoplanet Archive, last updated 2018-11-26. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HD 99706 c
Is HD 99706 c habitable?
HD 99706 c is not known to orbit within the habitable zone of HD 99706, and as a cold gas giant it is an unlikely candidate for life as we know it.
How far away is HD 99706 c?
HD 99706 c is about 478 light-years from Earth in the constellation Ursa Major. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 8,414,560 years to get there.
How long is a year on HD 99706 c?
One orbit around HD 99706 takes 1,278.0 Earth days.
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