K2-21 c
A confirmed exoplanet orbiting K2-21.
Compared with Earth
- Size
- About 2.5 times Earth's width.
- Starlight
- About 5.1 times the starlight Earth gets from the Sun.
- Year
- A year here lasts about 16 Earth days.
Planet
- Radius
- 2.49 × Earth
- Mass
- Unknown
- Density
- Unknown
- Equilibrium temperature
- Unknown
- Starlight received
- 5.1 × Earth
- Orbital period
- 15.5 days
- Average distance from its star
- 0.107 AU
Star
- Host star
- K2-21
- Spectral class
- K — orange dwarf
- Surface temperature
- 4,222 K
- Radius
- 0.6468 × Sun
- Mass
- 0.676 × Sun
- Age
- Unknown
System
- Distance from Earth
- 272.8 light-years (83.64 parsecs)
- Stars in system
- 1
- Known planets
- 2
Discovery
- Year
- 2015
- Method
- Transit
- Facility
- K2
Data from the NASA Exoplanet Archive, synced October 14, 2026.