NASA's Hubble Space Telescope has captured the first-ever picture of a group of five star-like images of a single distant quasar. The multiple-image effect seen in the Hubble picture is produced by a process called gravitational lensing, in which the gravitational field of a massive object - in this case, a cluster of galaxies - bends and amplifies light from an object - in this case, a quasar - farther behind it. The image was based on data obtained by Tel Aviv University astronomers from the Hubble Space Telescope. The Israeli team included TAU doctoral student Keren Sharon, former student (now post-doctoral fellow at the California Institute of Technology) Dr. Eran Ofek, TAU Prof. Dan Maoz and Dr. Tom Broadhurst. The image shows a very distant cluster of galaxies seven billion light-years away whose mass acts as a giant natural lens that magnifies objects behind it - an effect predicted by Albert Einstein that has been finding widespread application in astronomy in the last two decades. It is the only case known in which an entire cluster of galaxies lenses a background quasar about 10 billion light years away. A quasar is an object at the center of a galaxy powered by a giant black hole.