The star
The star
K2-104
- Type
- M2.5e
- Surface
- ≈ 3,712 K
- Size
- 0.48 × the Sun
- Mass
- 0.51 × the Sun
- Brightness
- 0.0368 × the Sun
- Habitable zone
- 0.156–0.402 AU
The planets
K2-104
K2-104 b
- Year
- 1.97 days
- Distance from star
- 0.0242 AU
- Mass
- 3.9 Earths
- Size
- 1.8 × Earth
- Temperature
- ≈ 798 K (+525 °C)
- Found
- 2016, 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.