Exoplanet
Kepler-399 d
2,415.31 light-years
- Discovery
- Transit · 2014
- Radius
- 1.89 (+1.01 / −1.01) Earth radii
- Mass
- 4.23 Earth masses
- Orbital period
- 58.0346 (+3.63 × 10⁻⁴ / −3.63 × 10⁻⁴) days
- Semi-major axis
- 0.261 AU
- Equilibrium temperature
- 486 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