HR 8799
A young A-type stellar system located in the constellation Pegasus, approximately 130 light-years from Earth. It hosts four directly imaged gas giant planets designated HR 8799 b, c, d, and e, making it the exoplanetary system with the greatest number of directly imaged planets confirmed to date. The system serves as an important natural laboratory for studying planetary formation and orbital dynamics.
Timeline (last 90 days)
A sequence of telescope images spanning approximately 12 years continuously recorded the actual trajectories of four planets orbiting the same star.
This set of images corresponds to the HR 8799 planetary system.
HR 8799 is a young A-type star located in the constellation Pegasus, approximately 130 light-years from Earth, with an estimated age of 30 to 60 million years.
In 2008, Marois et al. reported in Science the first direct imaging of three planets—b, c, and d—in the HR 8799 system.
The fourth planet of HR 8799, planet e, was confirmed in 2010, making it the exoplanetary system with the most directly imaged planets to date.
The masses of all four planets in HR 8799 are between 5 and 13 Jupiter masses, their orbital radii extend from approximately 15 AU to over 70 AU, and their orbital periods range from about 40 years to several hundred years.
The surface temperatures of HR 8799's planets are around 900 to 1200 Kelvin, and they emit relatively bright thermal radiation in the near-infrared band, which is the key physical condition enabling their direct imaging.
The 12-year image sequence shows light spots moving along closed orbits around the star, ruling out the possibility of background stars or imaging artifacts.
Due to its wide orbits and bright planets, HR 8799 has become the preferred natural laboratory for testing planet formation theories and orbital resonance stability models.
All Facts (9)
Due to its wide orbits and bright planets, HR 8799 has become the preferred natural laboratory for testing planet formation theories and orbital resonance stability models.
50%UnverifiedThis set of images corresponds to the HR 8799 planetary system.
50%UnverifiedHR 8799 is a young A-type star located in the constellation Pegasus, approximately 130 light-years from Earth, with an estimated age of 30 to 60 million years.
50%UnverifiedIn 2008, Marois et al. reported in Science the first direct imaging of three planets—b, c, and d—in the HR 8799 system.
50%UnverifiedThe fourth planet of HR 8799, planet e, was confirmed in 2010, making it the exoplanetary system with the most directly imaged planets to date.
50%UnverifiedThe masses of all four planets in HR 8799 are between 5 and 13 Jupiter masses, their orbital radii extend from approximately 15 AU to over 70 AU, and their orbital periods range from about 40 years to several hundred years.
50%UnverifiedThe surface temperatures of HR 8799's planets are around 900 to 1200 Kelvin, and they emit relatively bright thermal radiation in the near-infrared band, which is the key physical condition enabling their direct imaging.
50%UnverifiedThe 12-year image sequence shows light spots moving along closed orbits around the star, ruling out the possibility of background stars or imaging artifacts.
50%UnverifiedA sequence of telescope images spanning approximately 12 years continuously recorded the actual trajectories of four planets orbiting the same star.
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