HD 75784 c
HD 75784 c is a cold gas giant orbiting HD 75784 in the constellation Cancer. It lies about 279 light-years from Earth and was discovered in 2018 using the radial velocity method.
Is HD 75784 c in the Habitable Zone?
HD 75784 c orbits beyond the outer edge of the habitable zone of HD 75784. At that distance, any surface water would almost certainly be frozen.
Habitable zone of HD 75784: 1.901–4.622 AU (conservative: 2.408–4.382 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 75784 c — one full orbit around HD 75784 — lasts 7,900.0 Earth days, longer than Jupiter's 12-year orbit. It orbits at an average distance of 8.400 AU. Its orbit is highly elliptical (eccentricity 0.49), swinging dramatically closer to and farther from its star.
How Was HD 75784 c Discovered?
HD 75784 c was discovered in 2018 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 75784 c?
HD 75784 c is 278.6 light-years (85.4 parsecs) from Earth. Light arriving here tonight left the planet around the year 1748. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 4,903,360 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 75784 c scores 0.16, ranking #4,151 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: HD 75784
HD 75784
- Surface temperature
- 4,867 K (Sun: 5,772 K)
- Mass
- 1.26 M☉
- Radius
- 3.40 R☉
The HD 75784 Planetary System
HD 75784 c is one of 2 known planets in the HD 75784 system. Its siblings:
- HD 75784 b (Cold Gas Giant)
HD 75784 c — Complete Data
| Mass (best estimate) | 1,792.56 Earth masses |
|---|---|
| Orbital period | 7,900.00 days |
| Orbital distance | 8.400 AU |
| Eccentricity | 0.489 |
| Earth Similarity Index | 0.16 |
| Distance from Earth | 278.6 light-years (85.4 parsecs) |
| Constellation | Cancer |
| Discovery method | Radial Velocity |
| Discovery facility | W. M. Keck Observatory |
| Discovery year | 2018 |
Data: NASA Exoplanet Archive, last updated 2018-12-03. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HD 75784 c
Is HD 75784 c habitable?
No — HD 75784 c orbits outside the habitable zone of HD 75784 and is likely too cold for liquid water on its surface.
How far away is HD 75784 c?
HD 75784 c is about 279 light-years from Earth in the constellation Cancer. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 4,903,360 years to get there.
How long is a year on HD 75784 c?
One orbit around HD 75784 takes 7,900.0 Earth days.
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