Colour version...LRGB 50m 15m 15m 20m 3x3 bin
Double Quasar 0957+561 - an example of gravitational lensing...(best viewed as Original)
Gravitational lensing was long predicted by Einstein's General Theory of Relativity - if gravity can be properly viewed as a bending of space produced by mass, then light rays should change their direction upon passing a massive object. In extreme cases, we might expect to see multiple images of the same object, formed by light that has gone around opposite sides of the intervening mass. The first examples of such lensing involved quasars, as the brightest objects seen at large distances. This quasar was the first confirmed lensing case, the double quasar 0957+561. It was found while searching for counterparts of radio sources, when two candidates showed up only 6 arcseconds apart (altered text from Wikipedia).
The picture was taken at Grafton, Ontario with C9.25 and ML8300 camera, by Lynn Hilborn, May 2010