Gliese 581 b
Planet· orbits the Sun
Gliese 581 b - the most massive confirmed planet here (~20 Earth masses), a warm Neptune-like world on a 5.4-day orbit. Never imaged.
Open in 3D viewSee Gliese 581 b in the live, interactive 3D map
Key facts
Mass
1.22 × 10²⁶ kg
20.5 M⊕
Year
5.37 Earth days
Distance from Gliese 581
5,968,955 km
Science
Physical
- Mass
- 1.22 × 10²⁶ kg · 20.5 M⊕
- Radius
- Not measured
Orbital
- Semi-major axis
- 5,968,955 km
- Eccentricity
- 0.03
- Inclination
- 0.00 °
- Orbital period
- 5.4 days
- Perihelion
- 5,789,886 km
- Aphelion
- 6,148,024 km
- Mean orbital velocity
- 80.8 km/s
Composition
- Bulk composition
- A warm Neptune-mass world (~20 Earth masses), likely with a thick gas envelope; never imaged.
- Cloud appearance
- Appearance based on ESO/M. Kornmesser's artist's concept. No spacecraft has imaged this world, so its real appearance is unknown — The banded clouds shown are a representation of its class, shown only in Vision mode; Realism shows a plain spectral colour.
Radiation & temperature
- Insolation
- 7.79 S⊕ · 7.79× the sunlight Earth receives
- Equilibrium temperature
- 464 K (191 °C)
Discovery & history
- Method
- Radial-velocity detection (stellar wobble)
- Name
- Designated 'b' as the second planet found around its star, following the IAU convention of lettering planets in discovery order from 'b'.
The first planet found at Gliese 581, announced in 2005 - a Neptune-mass world close to the star.
Images
No official imagery available — this object has never been visited and no officially-licensed depiction exists.