The star
The star
K2-155
- Type
- K7
- Surface
- ≈ 4,258 K
- Size
- 0.58 × the Sun
- Mass
- 0.65 × the Sun
- Brightness
- 0.059 × the Sun
- Habitable zone
- 0.196–0.489 AU
The planets
K2-155
K2-155 b
- Year
- 6.34 days
- Distance from star
- 0.0562 AU
- Mass
- 3.9 Earths
- Size
- 1.8 × Earth
- Temperature
- ≈ 708 K (+435 °C)
- Found
- 2018, transit (K2)
K2-155
K2-155 c
- Year
- 13.85 days
- Distance from star
- 0.0946 AU
- Mass
- 7.3 Earths
- Size
- 2.6 × Earth
- Temperature
- ≈ 583 K (+310 °C)
- Found
- 2018, transit (K2)
K2-155
K2-155 d
- Year
- 40.72 days
- Distance from star
- 0.194 AU
- Mass
- 4.3 Earths
- Size
- 1.9 × Earth
- Temperature
- ≈ 381 K (+108 °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.