Exoplanet
K2-21 b
272.81 light-years
- Discovery
- Transit · 2015
- Radius
- 1.84 (+0.1 / −0.1) Earth radii
- Mass
- 4.04 Earth masses
- Orbital period
- 9.325 (+3.79 × 10⁻⁴ / −4.03 × 10⁻⁴) days
- Semi-major axis
- 0.076 (+2 × 10⁻³ / −3 × 10⁻³) AU
- Equilibrium temperature
- 500 K
- Mass provenance
- M-R relationship
Measurements may come from different studies and need not form one self-consistent model. “Msini” is a minimum mass; a mass inferred from radius is an estimate. Equilibrium temperature is a model estimate, not a measured surface temperature or evidence of habitability.
NASA archive record and references ↗
Snapshot retrieved: 2026-10-11T04:15:07.688253+00:00