HD 155358 c
HD 155358 c is a cold gas giant orbiting HD 155358 in the constellation Hercules. It lies about 142 light-years from Earth and was discovered in 2007 using the radial velocity method.
Is HD 155358 c in the Habitable Zone?
HD 155358 c orbits inside the inner edge of the habitable zone of HD 155358. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of HD 155358: 1.073–2.521 AU (conservative: 1.360–2.390 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 155358 c — one full orbit around HD 155358 — lasts 391.9 Earth days, longer than an Earth year. It orbits at an average distance of 1.020 AU — comparable to the inner Solar System. Its orbit is mildly elliptical (eccentricity 0.16).
How Was HD 155358 c Discovered?
HD 155358 c was discovered in 2007 using the radial velocity method, with observations from McDonald 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 155358 c?
HD 155358 c is 142.3 light-years (43.6 parsecs) from Earth. Light arriving here tonight left the planet around the year 1884. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 2,504,480 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 155358 c scores 0.35, ranking #782 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: HD 155358
HD 155358
- Surface temperature
- 5,905 K (Sun: 5,772 K)
- Mass
- 1.15 M☉
- Radius
- 1.38 R☉
The HD 155358 Planetary System
HD 155358 c is one of 2 known planets in the HD 155358 system. Its siblings:
- HD 155358 b (Cold Gas Giant)
HD 155358 c — Complete Data
| Mass (best estimate) | 261.00 Earth masses |
|---|---|
| Orbital period | 391.90 days |
| Orbital distance | 1.020 AU |
| Eccentricity | 0.160 |
| Earth Similarity Index | 0.35 |
| Distance from Earth | 142.3 light-years (43.6 parsecs) |
| Constellation | Hercules |
| Discovery method | Radial Velocity |
| Discovery facility | McDonald Observatory |
| Discovery year | 2007 |
Data: NASA Exoplanet Archive, last updated 2019-01-28. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HD 155358 c
Is HD 155358 c habitable?
No — HD 155358 c orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is HD 155358 c?
HD 155358 c is about 142 light-years from Earth in the constellation Hercules. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 2,504,480 years to get there.
How long is a year on HD 155358 c?
One orbit around HD 155358 takes 391.9 Earth days.
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