HR 8799This relatively young white star has one of the most massive dust disks of all stars within a range of 300 light-years. And it has three exoplanets, which in November 2008 all have been photographed in one image (in near infrared), the first image of multiple exoplanets. Yet c and d could be small brown dwarfs as well. The planets: HR 8799 d: 10 times mass of Jupiter, 1,2 times its diameter, 24 AU distance, 100 years orbit period. HR 8799 c: 10 times mass of Jupiter, 1,2 times its diameter, 38 AU distance, 189 years orbit period. HR 8799 b: 7 times mass of Jupiter, 1,1 times its diameter, 68 AU distance, 465 years orbit period. Constellation: Pegasus Age: 60 million years Distance: 128 light-years Spectral class: A5 Visual magnitude: 5.69 Luminosity: 5 * Sun Mass: 1.5 * Sun Back: List of Exoplanets 11/13/2008 |
The arrows show the paths of the planets within four years. Photo: Keck Observatory / Christian Marois and Bruce Macintosh |
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