The star
The star
Kepler-186
- Type
- M1
- Surface
- ≈ 3,788 K
- Size
- 0.47 × the Sun
- Mass
- 0.48 × the Sun
- Brightness
- 0.0412 × the Sun
- Habitable zone
- 0.165–0.423 AU
The planets
Kepler-186
Kepler-186 b
- Year
- 3.89 days
- Distance from star
- 0.0343 AU
- Mass
- 1.2 Earths
- Size
- 1.1 × Earth
- Temperature
- ≈ 571 K (+298 °C)
- Found
- 2014, transit (Kepler)
Kepler-186
Kepler-186 c
- Year
- 7.27 days
- Distance from star
- 0.0451 AU
- Mass
- 2.1 Earths
- Size
- 1.2 × Earth
- Temperature
- ≈ 464 K (+191 °C)
- Found
- 2014, transit (Kepler)
Kepler-186
Kepler-186 d
- Year
- 13.34 days
- Distance from star
- 0.0781 AU
- Mass
- 2.5 Earths
- Size
- 1.4 × Earth
- Temperature
- ≈ 379 K (+106 °C)
- Found
- 2014, transit (Kepler)
Kepler-186
Kepler-186 e
- Year
- 22.41 days
- Distance from star
- 0.11 AU
- Mass
- 2.1 Earths
- Size
- 1.3 × Earth
- Temperature
- ≈ 319 K (+46 °C)
- Found
- 2014, transit (Kepler)
Kepler-186
Kepler-186 f
- Year
- 129.94 days
- Distance from star
- 0.432 AU
- Mass
- 1.7 Earths
- Size
- 1.2 × Earth
- Temperature
- ≈ 177 K (-96 °C)
- Found
- 2014, transit (Kepler)
Masses found by the wobble method are minimums, because the orbit's tilt is unknown. Temperatures are equilibrium estimates for a bare planet, before any atmosphere.
How we know
The shadow
The planet passes in front of its star and dims it by a fraction of a percent, every orbit. The dip gives the planet's size and year.
Sources
- Planet and star parameters: NASA Exoplanet Archive, Planetary Systems Composite Parameters, retrieved 1 Nov 2026. This research has made use of the NASA Exoplanet Archive, which is operated by the California Institute of Technology, under contract with NASA under the Exoplanet Exploration Program.
- Position: HYG Database v4.1 (CC BY-SA 4.0).
- Habitable zone: a simple estimate from the star's brightness (√L × 0.95 to 1.67 AU), shown as a guide.