The star
The star
K2-381
- Type
- orange dwarf
- Surface
- ≈ 4,473 K
- Size
- 0.68 × the Sun
- Mass
- 0.75 × the Sun
- Brightness
- 0.182 × the Sun
- Habitable zone
- 0.342–0.845 AU
The planets
K2-381
K2-381 b
- Year
- 7.94 days
- Distance from star
- 0.0709 AU
- Mass
- 1.3 Earths
- Size
- 1.1 × Earth
- Found
- 2022, transit (K2)
K2-381
K2-381 c
- Year
- 16.03 days
- Distance from star
- 0.113 AU
- Mass
- 4.7 Earths
- Size
- 2 × Earth
- Found
- 2022, transit (K2)
K2-381
K2-381 d
- Year
- 26.80 days
- Distance from star
- 0.16 AU
- Mass
- 3.5 Earths
- Size
- 1.7 × Earth
- Found
- 2022, transit (K2)
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.