Gliese 876 b
Planet· orbits Gliese 876
Gliese 876 b - the largest planet of the system (~2.3 Jupiter masses), on a 61-day orbit; the first planet ever found around a red dwarf. Never imaged.
Open in 3D viewSee Gliese 876 b in the live, interactive 3D map
Key facts
Mass
4.32 × 10²⁷ kg
2.28 M♃ (723 M⊕)
Year
61.03 Earth days
Distance from Gliese 876
0.208 AU
Science
Physical
- Mass
- 4.32 × 10²⁷ kg · 2.28 M♃ (723 M⊕)
- Radius
- Not measured
- No transit — radius is a model estimate for a ~2.3-Jupiter gas giant; no density is quoted.
Orbital
- Semi-major axis
- 0.208 AU
- From the NASA Exoplanet Archive (radial-velocity orbit)
- Eccentricity
- 0.032
- From the NASA Exoplanet Archive (radial-velocity orbit)
- Inclination
- 0.00 °
- From the NASA Exoplanet Archive (radial-velocity orbit)
- Orbital period
- 61.0 days
- From the NASA Exoplanet Archive (radial-velocity orbit)
- Perihelion
- 0.202 AU
- Computed from the orbital elements
- Aphelion
- 0.215 AU
- Computed from the orbital elements
- Mean orbital velocity
- 37.1 km/s
- Computed from the orbital elements
Composition
- Bulk composition
- A gas giant of true (dynamical) mass ~2.3 Jupiter — hydrogen and helium; the first planet ever found around an M dwarf (1998). 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 Visual mode; Realism shows a plain spectral colour.
Radiation & temperature
- Insolation
- 0.286 S⊕ · 29% of the sunlight Earth receives
- Computed from Gliese 876's luminosity and the orbital distance (inverse-square; Earth's sunlight = 1).
- Equilibrium temperature
- 191 K (-82 °C)
- Computed model value for its 61-day orbit — not measured.
Discovery & history
- Discovered
- June 22, 1998
- Method
- Radial-velocity detection (stellar wobble)
- Name
- Designated 'b' under the IAU convention that letters a star's planets 'b', 'c', 'd'... in the order they are discovered (the star itself is the unwritten 'a').
Detected in 1998 by teams at Geneva and San Francisco State - the first planet known to orbit an M dwarf, opening the study of the Galaxy's commonest planet hosts.
Images
No official imagery available — this object has never been visited and no officially-licensed depiction exists.