The star
The star
K2-136
- Type
- K5.5
- Surface
- ≈ 4,500 K
- Size
- 0.68 × the Sun
- Mass
- 0.74 × the Sun
- Brightness
- 0.167 × the Sun
- Habitable zone
- 0.327–0.808 AU
The planets
K2-136
K2-136 b
- Year
- 7.98 days
- Distance from star
- 0.0707 AU
- Mass
- 4.3 Earths
- Size
- 1 × Earth
- Temperature
- ≈ 610 K (+337 °C)
- Found
- 2017, transit (K2)
K2-136
K2-136 c
- Year
- 17.31 days
- Distance from star
- 0.118 AU
- Mass
- 18 Earths
- Size
- 3 × Earth
- Temperature
- ≈ 470 K (+197 °C)
- Found
- 2017, transit (K2)
K2-136
K2-136 d
- Year
- 25.57 days
- Distance from star
- 0.154 AU
- Mass
- 3 Earths
- Size
- 1.6 × Earth
- Temperature
- ≈ 420 K (+147 °C)
- Found
- 2017, 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.