The star
The star
K2-199
- Type
- orange dwarf
- Surface
- ≈ 4,491 K
- Size
- 0.68 × the Sun
- Mass
- 0.71 × the Sun
- Brightness
- 0.185 × the Sun
- Habitable zone
- 0.344–0.85 AU
The planets
K2-199
K2-199 b
- Year
- 3.23 days
- Distance from star
- 0.0382 AU
- Mass
- 6.9 Earths
- Size
- 1.7 × Earth
- Temperature
- ≈ 913 K (+640 °C)
- Found
- 2018, transit (K2)
K2-199
K2-199 c
- Year
- 7.37 days
- Distance from star
- 0.0662 AU
- Mass
- 12 Earths
- Size
- 2.9 × Earth
- Temperature
- ≈ 694 K (+421 °C)
- Found
- 2018, 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.