Gliese 251 b
Planet· orbits Gliese 251
Gliese 251 b - a warm super-Earth (minimum mass ~3.9 Earth) on a 14-day orbit near the inner temperate zone, one of the closest such planets. RV-only: minimum mass, model-estimate size, never imaged.
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Key facts
Minimum mass
2.30 × 10²⁵ kg
3.85 M⊕
Year
14.24 Earth days
Distance from Gliese 251
12,087,508 km
Science
Physical
- Minimum mass (m·sin i)
- 2.30 × 10²⁵ kg · 3.85 M⊕
- Radial-velocity detection measures m·sin i; the true mass depends on the unknown orbital inclination.
- Radius
- Not measured
- No transit — radius is a model estimate for a ~3.9-Earth-mass world; true size unknown.
Orbital
- Semi-major axis
- 12,087,508 km
- From the NASA Exoplanet Archive (radial-velocity orbit)
- Eccentricity
- 0
- From the NASA Exoplanet Archive (radial-velocity orbit)
- Inclination
- 0.00 °
- From the NASA Exoplanet Archive (radial-velocity orbit)
- Orbital period
- 14.2 days
- From the NASA Exoplanet Archive (radial-velocity orbit)
- Perihelion
- 12,087,508 km
- Computed from the orbital elements
- Aphelion
- 12,087,508 km
- Computed from the orbital elements
- Mean orbital velocity
- 61.7 km/s
- Computed from the orbital elements
Composition
- Bulk composition
- A warm super-Earth of minimum mass ~3.9 Earth, one of the closest such planets; never imaged.
- Surface appearance
- Appearance based on ESO/M. Kornmesser's artist's concept. No spacecraft has imaged this world, so its real appearance is unknown — The surface shown is an artistic representation, shown only in Visual mode; Realism shows a plain spectral colour.
Radiation & temperature
- Insolation
- 2.37 S⊕ · 2.37× the sunlight Earth receives
- Computed from Gliese 251's luminosity and the orbital distance (inverse-square; Earth's sunlight = 1).
- Equilibrium temperature
- 336 K (63 °C)
- Computed model value for its orbit near the inner temperate zone — not measured.
Discovery & history
- 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').
Announced in 2020 by the CARMENES radial-velocity survey as a nearby temperate super-Earth.
Images
No official imagery available — this object has never been visited and no officially-licensed depiction exists.