GJ 581 b
📋 A written introduction is coming — for now this page shows official values only.
Planet
- Host star
- GJ 581
- Distance from Earth
- 6.2981 pc (≈ 20.5 light-years)
- NASA planet type
- Neptune-like
- Radius (Earth = 1)
- 4.79
- Mass (Earth = 1)
- 20.5
- Orbital period
- 5.3686 days
- Semi-major axis
- 0.0399 AU
- Eccentricity
- 0.0342
- Equilibrium temperature
- 464.32 K
- Discovery method
- Radial Velocity
- Discovery year
- 2,005
- Discovery facility
- La Silla Observatory
- Host spectral type
- M3.0 V
- Host temperature
- 3,500 K
- Host radius (Sun = 1)
- 0.302
- Host mass (Sun = 1)
- 0.295
- Host brightness
- 10.57 mag
Source:NASA Exoplanet Archive (Caltech/IPAC) · checked 2026-11-02 ↗NASA Science · checked 2026-11-02 ↗NASA Exoplanet Archive (Caltech/IPAC) · checked 2026-11-02 ↗
In everyday life
- Light from this object takes about 21 years to reach Earth — the light you see tonight left around AD 2005 (official distance ÷ speed of light).
- Its radius is about 4.8 times Earth's (NASA Exoplanet Archive).
- One orbit takes about 5.4 Earth days — that is this planet's year.
Worked out from this object's official values.