Kepler-56 c
Kepler-56 c is a cold gas giant orbiting Kepler-56 in the constellation Cygnus. It lies about 2,978 light-years from Earth and was discovered in 2012 using the transit method.
How Big Is Kepler-56 c?
Kepler-56 c has a radius of 9.80 times that of Earth, or 0.87 times the radius of Jupiter. Its mass is 181 times that of Earth, giving it a density of 1.06 g/cm³ — closer to gas planets like Jupiter (1.33 g/cm³).
Is Kepler-56 c in the Habitable Zone?
Kepler-56 c orbits inside the inner edge of the habitable zone of Kepler-56. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of Kepler-56: 2.318–5.645 AU (conservative: 2.936–5.352 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 Kepler-56 c — one full orbit around Kepler-56 — lasts 21.4 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.165 AU — closer to its star than Mercury is to the Sun.
How Was Kepler-56 c Discovered?
Kepler-56 c was discovered in 2012 using the transit method, with observations from Kepler.
The transit method watches a star for the tiny, regular dip in brightness that occurs when a planet crosses in front of it. The depth and timing of these dips reveal the planet's size and orbital period.
How Far Away Is Kepler-56 c?
Kepler-56 c is 2,977.8 light-years (913.0 parsecs) from Earth. Light arriving here tonight left the planet about 2,978 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 52,409,280 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. Kepler-56 c scores 0.09, ranking #4,503 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: Kepler-56
Kepler-56
- Surface temperature
- 4,819 K (Sun: 5,772 K)
- Radius
- 4.22 R☉
The Kepler-56 Planetary System
Kepler-56 c is one of 3 known planets in the Kepler-56 system. Its siblings:
- Kepler-56 b (Cold Gas Giant)
- Kepler-56 d (Cold Gas Giant)
Kepler-56 c — Complete Data
| Radius | 9.800 Earth radii (0.874 Jupiter radii) |
|---|---|
| Mass | 181.00 Earth masses (0.570 Jupiter masses) |
| Density | 1.06 g/cm³ (Earth: 5.51) |
| Orbital period | 21.40 days |
| Orbital distance | 0.165 AU |
| Earth Similarity Index | 0.09 |
| Distance from Earth | 2,977.8 light-years (913.0 parsecs) |
| Constellation | Cygnus |
| Discovery method | Transit |
| Discovery facility | Kepler |
| Discovery year | 2012 |
Data: NASA Exoplanet Archive, last updated 2014-05-14. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About Kepler-56 c
Is Kepler-56 c habitable?
No — Kepler-56 c orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is Kepler-56 c?
Kepler-56 c is about 2,978 light-years from Earth in the constellation Cygnus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 52,409,280 years to get there.
How big is Kepler-56 c compared to Earth?
Kepler-56 c has 9.80 times the radius of Earth and about 181 times its mass.
How long is a year on Kepler-56 c?
One orbit around Kepler-56 takes 21.4 Earth days — short enough that 17 of its years would fit into one Earth year.
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