The star
The star
Kepler-338
- Type
- yellow star
- Surface
- ≈ 5,923 K
- Size
- 1.74 × the Sun
- Mass
- 1.10 × the Sun
- Brightness
- 3.85 × the Sun
- Habitable zone
- 1.46–3.43 AU
The planets
Kepler-338
Kepler-338 e
- Year
- 9.34 days
- Distance from star
- 0.0898 AU
- Mass
- 8.5 Earths
- Size
- 1.6 × Earth
- Temperature
- ≈ 1143 K (+870 °C)
- Found
- 2014, transit (Kepler)
Kepler-338
Kepler-338 b
- Year
- 13.73 days
- Distance from star
- 0.117 AU
- Mass
- 31 Earths
- Size
- 2.4 × Earth
- Temperature
- ≈ 1005 K (+732 °C)
- Found
- 2014, transit (Kepler)
Kepler-338
Kepler-338 c
- Year
- 24.31 days
- Distance from star
- 0.172 AU
- Mass
- 6.1 Earths
- Size
- 2.3 × Earth
- Temperature
- ≈ 831 K (+558 °C)
- Found
- 2014, transit (Kepler)
Kepler-338
Kepler-338 d
- Year
- 44.43 days
- Distance from star
- 0.257 AU
- Mass
- 9.3 Earths
- Size
- 3 × Earth
- Temperature
- ≈ 680 K (+407 °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.