K2-121 b
A confirmed exoplanet orbiting K2-121.
Compared with Earth
- Size
- About 7.2 times Earth's width.
- Mass
- About 51 times Earth's mass.
- Temperature
- About 443 °C (829 °F) from starlight alone, against -18 °C (-1 °F) for Earth measured the same way.
- Starlight
- About 63 times the starlight Earth gets from the Sun.
- Year
- A year here lasts about 5.2 Earth days.
Planet
- Radius
- 7.16 × Earth
- Mass
- 51 × Earth
- Density
- 0.7 g/cm³
- Equilibrium temperature
- 716 K
- Starlight received
- 62.5 × Earth
- Orbital period
- 5.186 days
- Average distance from its star
- Unknown
Star
- Host star
- K2-121
- Spectral class
- K — orange dwarf
- Surface temperature
- 4,526 K
- Radius
- 0.675 × Sun
- Mass
- 0.71 × Sun
- Age
- Unknown
System
- Distance from Earth
- 552.5 light-years (169.4 parsecs)
- Stars in system
- 1
- Known planets
- 1
Discovery
- Year
- 2017
- Method
- Transit
- Facility
- K2
Data from the NASA Exoplanet Archive, synced October 14, 2026.