Exoplanet
HAT-P-21 b
904.36 light-years
- Discovery
- Transit · 2010
- Radius
- 12.442 (+1.7934 / −1.7934) Earth radii
- Mass
- 1,547.8321 (+498.9931 / −498.9931) Earth masses
- Orbital period
- 4.1245 (+7 × 10⁻⁶ / −7 × 10⁻⁶) days
- Semi-major axis
- 0.0504 (+6.7 × 10⁻⁴ / −6.7 × 10⁻⁴) AU
- Equilibrium temperature
- 1,367 (+27 / −27) K
- Mass provenance
- Mass
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