HR 8799 planetary system
Three planets (b, c, and d) and newly discovered planet "e" orbit a star some 129 light years from Earth. The curved arrows represent the coming 10 years of orbital motion for the planets. 20 AU refers to 20 times the distance from the Earth to the sun. This image was obtained using the W.M. Keck II telescope at Mauna Kea Observatory in Hawaii.
(Credit: NRC-HIA, C. Marois, and Keck Observatory)
Download Photo (20.7 kB)