Kepler-187 b
Kepler-187 b is a super-Earth orbiting Kepler-187 in the constellation Cygnus. It lies about 3,728 light-years from Earth and was discovered in 2014 using the transit method.
How Big Is Kepler-187 b?
Kepler-187 b has a radius of 1.41 times that of Earth.
Is Kepler-187 b in the Habitable Zone?
Kepler-187 b orbits inside the inner edge of the habitable zone of Kepler-187. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of Kepler-187: 1.057–2.471 AU (conservative: 1.339–2.343 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-187 b — one full orbit around Kepler-187 — lasts 4.94 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.059 AU — closer to its star than Mercury is to the Sun.
How Was Kepler-187 b Discovered?
Kepler-187 b was discovered in 2014 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-187 b?
Kepler-187 b is 3,728.0 light-years (1,143.0 parsecs) from Earth. Light arriving here tonight left the planet about 3,728 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 65,612,800 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-187 b scores 0.28, ranking #2,099 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: Kepler-187
Kepler-187
- Surface temperature
- 6,105 K (Sun: 5,772 K)
- Radius
- 1.29 R☉
The Kepler-187 Planetary System
Kepler-187 b is one of 2 known planets in the Kepler-187 system. Its siblings:
- Kepler-187 c (Mini Neptune)
Kepler-187 b — Complete Data
| Radius | 1.410 Earth radii (0.126 Jupiter radii) |
|---|---|
| Orbital period | 4.94 days |
| Orbital distance | 0.059 AU |
| Earth Similarity Index | 0.28 |
| Distance from Earth | 3,728.0 light-years (1,143.0 parsecs) |
| Constellation | Cygnus |
| Discovery method | Transit |
| Discovery facility | Kepler |
| Discovery year | 2014 |
Data: NASA Exoplanet Archive, last updated 2014-05-14. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About Kepler-187 b
Is Kepler-187 b habitable?
No — Kepler-187 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is Kepler-187 b?
Kepler-187 b is about 3,728 light-years from Earth in the constellation Cygnus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 65,612,800 years to get there.
How big is Kepler-187 b compared to Earth?
Kepler-187 b has 1.41 times the radius of Earth.
How long is a year on Kepler-187 b?
One orbit around Kepler-187 takes 4.9 Earth days — short enough that 74 of its years would fit into one Earth year.
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