Kepler-27 c
Kepler-27 c is a Neptune-like planet orbiting Kepler-27 in the constellation Cygnus. It lies about 3,406 light-years from Earth and was discovered in 2011 using the transit method.
How Big Is Kepler-27 c?
Kepler-27 c has a radius of 4.90 times that of Earth. Its mass is 4,386 times that of Earth.
Is Kepler-27 c in the Habitable Zone?
Kepler-27 c orbits inside the inner edge of the habitable zone of Kepler-27. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of Kepler-27: 0.522–1.250 AU (conservative: 0.661–1.185 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-27 c — one full orbit around Kepler-27 — lasts 31.3 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.191 AU — closer to its star than Mercury is to the Sun.
How Was Kepler-27 c Discovered?
Kepler-27 c was discovered in 2011 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-27 c?
Kepler-27 c is 3,406.2 light-years (1,044.4 parsecs) from Earth. Light arriving here tonight left the planet about 3,406 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 59,949,120 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-27 c scores 0.24, ranking #3,415 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: Kepler-27
Kepler-27
- Surface temperature
- 5,251 K (Sun: 5,772 K)
- Mass
- 0.93 M☉
- Radius
- 0.82 R☉
The Kepler-27 Planetary System
Kepler-27 c is one of 3 known planets in the Kepler-27 system. Its siblings:
- Kepler-27 b (Super Earth)
- Kepler-27 d (Mini Neptune)
Kepler-27 c — Complete Data
| Radius | 4.900 Earth radii (0.437 Jupiter radii) |
|---|---|
| Mass | 4,385.87 Earth masses (13.800 Jupiter masses) |
| Orbital period | 31.33 days |
| Orbital distance | 0.191 AU |
| Earth Similarity Index | 0.24 |
| Distance from Earth | 3,406.2 light-years (1,044.4 parsecs) |
| Constellation | Cygnus |
| Discovery method | Transit |
| Discovery facility | Kepler |
| Discovery year | 2011 |
Data: NASA Exoplanet Archive, last updated 2014-05-14. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About Kepler-27 c
Is Kepler-27 c habitable?
No — Kepler-27 c orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is Kepler-27 c?
Kepler-27 c is about 3,406 light-years from Earth in the constellation Cygnus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 59,949,120 years to get there.
How big is Kepler-27 c compared to Earth?
Kepler-27 c has 4.90 times the radius of Earth and about 4,386 times its mass.
How long is a year on Kepler-27 c?
One orbit around Kepler-27 takes 31.3 Earth days — short enough that 12 of its years would fit into one Earth year.
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