Kepler-56 d
Kepler-56 d 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 2016 using the radial velocity method.
Is Kepler-56 d in the Habitable Zone?
Kepler-56 d 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 d — one full orbit around Kepler-56 — lasts 1,002.0 Earth days, longer than an Earth year. It orbits at an average distance of 2.160 AU. Its orbit is mildly elliptical (eccentricity 0.20).
How Was Kepler-56 d Discovered?
Kepler-56 d was discovered in 2016 using the radial velocity method, with observations from Multiple Observatories.
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 Kepler-56 d?
Kepler-56 d 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 d scores 0.36, ranking #663 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 d is one of 3 known planets in the Kepler-56 system. Its siblings:
- Kepler-56 b (Cold Gas Giant)
- Kepler-56 c (Cold Gas Giant)
Kepler-56 d — Complete Data
| Mass (best estimate) | 1,784.00 Earth masses |
|---|---|
| Orbital period | 1,002.00 days |
| Orbital distance | 2.160 AU |
| Eccentricity | 0.200 |
| Earth Similarity Index | 0.36 |
| Distance from Earth | 2,977.8 light-years (913.0 parsecs) |
| Constellation | Cygnus |
| Discovery method | Radial Velocity |
| Discovery facility | Multiple Observatories |
| Discovery year | 2016 |
Data: NASA Exoplanet Archive, last updated 2016-10-12. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About Kepler-56 d
Is Kepler-56 d habitable?
No — Kepler-56 d orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is Kepler-56 d?
Kepler-56 d 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 long is a year on Kepler-56 d?
One orbit around Kepler-56 takes 1,002.0 Earth days.
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