The star
The star
Kepler-229
- Type
- orange dwarf
- Surface
- ≈ 5,120 K
- Size
- 0.73 × the Sun
- Mass
- 0.81 × the Sun
- Brightness
- 0.29 × the Sun
- Habitable zone
- 0.419–1.01 AU
The planets
Kepler-229
Kepler-229 b
- Year
- 6.25 days
- Distance from star
- 0.062 AU
- Mass
- 5.5 Earths
- Size
- 2.2 × Earth
- Temperature
- ≈ 823 K (+550 °C)
- Found
- 2014, transit (Kepler)
Kepler-229
Kepler-229 c
- Year
- 16.07 days
- Distance from star
- 0.117 AU
- Mass
- 22 Earths
- Size
- 4.9 × Earth
- Temperature
- ≈ 600 K (+327 °C)
- Found
- 2014, transit (Kepler)
Kepler-229
Kepler-229 d
- Year
- 41.19 days
- Distance from star
- 0.22 AU
- Mass
- 14 Earths
- Size
- 3.9 × Earth
- Temperature
- ≈ 439 K (+166 °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.