The star
The star
Kepler-381
- Type
- white star
- Surface
- ≈ 6,197 K
- Size
- 2.19 × the Sun
- Mass
- 1.20 × the Sun
- Brightness
- 3.27 × the Sun
- Habitable zone
- 1.32–3.08 AU
The planets
Kepler-381
Kepler-381 b
- Year
- 5.63 days
- Distance from star
- 0.066 AU
- Mass
- 0.94 Earths
- Size
- 0.99 × Earth
- Temperature
- ≈ 1576 K (+1303 °C)
- Found
- 2014, transit (Kepler)
Kepler-381
Kepler-381 d
- Year
- 8.26 days
- Distance from star
- 0.0836 AU
- Mass
- 1.2 Earths
- Size
- 1.1 × Earth
- Temperature
- ≈ 1387 K (+1114 °C)
- Found
- 2021, transit (Kepler)
Kepler-381
Kepler-381 c
- Year
- 13.39 days
- Distance from star
- 0.117 AU
- Mass
- 1.5 Earths
- Size
- 1.1 × Earth
- Temperature
- ≈ 1180 K (+907 °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.