HR 8799 b
Planet· orbits the Sun
HR 8799 b — the outermost imaged giant (~5-7 Jupiter masses), circling far out at ~68 AU over roughly 460 years. The faintest and easiest to separate from the star, it was a key part of the first family portrait of another planetary system. Size and mass are model estimates, so no density is quoted.
Open in 3D viewSee HR 8799 b in the live, interactive 3D map
Key facts
Mass
1.19 × 10²⁸ kg
6.29 M♃ (2,000 M⊕)
Year
465 Earth years
170,000 Earth days
Distance from HR 8799
68 AU
Science
Physical
- Mass
- 1.19 × 10²⁸ kg · 6.29 M♃ (2,000 M⊕)
- Radius
- Not measured
Orbital
- Semi-major axis
- 68 AU
- Eccentricity
- 0.02
- Inclination
- 0.00 °
- Orbital period
- 465.43 years
- Perihelion
- 66.6 AU
- Aphelion
- 69.4 AU
- Mean orbital velocity
- 4.35 km/s
Composition
- Bulk composition
- A young gas giant of ~5–7 Jupiter masses circling far out at ~68 AU, the faintest and outermost of HR 8799's four imaged worlds. Self-luminous at ~1,100 K; hydrogen/helium.
- Cloud appearance
- Appearance based on NASA/JPL-Caltech'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
- 0.00123 S⊕ · 1/814 of the sunlight Earth receives
Discovery & history
- Method
- Directly imaged
- Name
- Designated 'b' under the IAU planet-lettering convention; no IAU proper name has been assigned.
One of the three planets directly imaged around HR 8799 in 2008 — the outermost of the first multi-planet system ever photographed.
Images
Directly imaged only as a point of light beside HR 8799 — see the system view for the real Keck time-lapse and Hubble images that show all four planets. No telescope has resolved this planet's disk or surface.