Kepler-6 b
Kepler-6 b is a hot Jupiter orbiting Kepler-6 in the constellation Cygnus. It lies about 1,915 light-years from Earth and was discovered in 2009 using the transit method.
How Big Is Kepler-6 b?
Kepler-6 b has a radius of 14.62 times that of Earth, or 1.30 times the radius of Jupiter. Its mass is 212 times that of Earth, giving it a density of 0.40 g/cm³ — closer to gas planets like Jupiter (1.33 g/cm³).
Is Kepler-6 b in the Habitable Zone?
Kepler-6 b orbits inside the inner edge of the habitable zone of Kepler-6. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of Kepler-6: 1.005–2.376 AU (conservative: 1.273–2.253 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 ›
Temperature on Kepler-6 b
The equilibrium temperature of Kepler-6 b is about 1,460 K (1,187 °C) — hot enough to melt many metals. This estimate ignores any atmosphere, which could change surface temperatures dramatically — Earth's greenhouse effect adds about 33 °C.
Orbit and Year Length
A year on Kepler-6 b — one full orbit around Kepler-6 — lasts 3.23 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.049 AU — closer to its star than Mercury is to the Sun.
How Was Kepler-6 b Discovered?
Kepler-6 b was discovered in 2009 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-6 b?
Kepler-6 b is 1,914.7 light-years (587.0 parsecs) from Earth. Light arriving here tonight left the planet about 1,915 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 33,698,720 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-6 b scores 0.06, ranking #5,087 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: Kepler-6
Kepler-6
- Surface temperature
- 5,647 K (Sun: 5,772 K)
- Mass
- 1.21 M☉
- Radius
- 1.39 R☉
Planetary System
Kepler-6 b is the only planet known to orbit Kepler-6 so far.
Kepler-6 b — Complete Data
| Radius | 14.617 Earth radii (1.304 Jupiter radii) |
|---|---|
| Mass | 212.31 Earth masses (0.668 Jupiter masses) |
| Density | 0.40 g/cm³ (Earth: 5.51) |
| Orbital period | 3.23 days |
| Orbital distance | 0.049 AU |
| Equilibrium temperature | 1,460 K (1,187 °C) |
| Earth Similarity Index | 0.06 |
| Distance from Earth | 1,914.7 light-years (587.0 parsecs) |
| Constellation | Cygnus |
| Discovery method | Transit |
| Discovery facility | Kepler |
| Discovery year | 2009 |
Data: NASA Exoplanet Archive, last updated 2015-10-07. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About Kepler-6 b
Is Kepler-6 b habitable?
No — Kepler-6 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is Kepler-6 b?
Kepler-6 b is about 1,915 light-years from Earth in the constellation Cygnus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 33,698,720 years to get there.
How big is Kepler-6 b compared to Earth?
Kepler-6 b has 14.62 times the radius of Earth and about 212 times its mass.
How long is a year on Kepler-6 b?
One orbit around Kepler-6 takes 3.2 Earth days — short enough that 113 of its years would fit into one Earth year.
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