Pollux b
Planet· orbits Pollux
Pollux b (Thestias) - a super-Jupiter of at least ~2.3 Jupiter masses orbiting the orange giant Pollux every 590 days on a nearly circular path. Found from the star's wobble, its mass is a minimum and it has never been imaged.
Open in 3D viewSee Pollux b in the live, interactive 3D map
Key facts
Minimum mass
4.37 × 10²⁷ kg
2.3 M♃ (731 M⊕)
Year
590 Earth days
1.61 Earth years
Distance from Pollux
1.64 AU
Science
Physical
- Minimum mass (m·sin i)
- 4.37 × 10²⁷ kg · 2.3 M♃ (731 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 giant of at least ~2.3 Jupiter masses; true size unknown.
Orbital
- Semi-major axis
- 1.64 AU
- From the NASA Exoplanet Archive (radial-velocity orbit)
- Eccentricity
- 0.02
- From the NASA Exoplanet Archive (radial-velocity orbit)
- Inclination
- 0.00 °
- From the NASA Exoplanet Archive (radial-velocity orbit)
- Orbital period
- 589.6 days
- From the NASA Exoplanet Archive (radial-velocity orbit)
- Perihelion
- 1.61 AU
- Computed from the orbital elements
- Aphelion
- 1.67 AU
- Computed from the orbital elements
- Mean orbital velocity
- 30.3 km/s
- Computed from the orbital elements
Composition
- Bulk composition
- A giant planet (minimum mass ≥ ~2.3 Jupiter) of hydrogen and helium; found from the giant star's wobble and 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
- 15.2 S⊕ · 15.2× the sunlight Earth receives
- Computed from Pollux's luminosity and the orbital distance (inverse-square; Earth's sunlight = 1).
- Equilibrium temperature
- 550 K (277 °C)
- Computed model value for its 1.6-AU orbit around a luminous giant — 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 2006 after more than 25 years of radial-velocity monitoring at McDonald Observatory revealed a steady, periodic wobble in Pollux's light.
Images
No official imagery available — this object has never been visited and no officially-licensed depiction exists.