DLR Logo
  Home|Textversion|Imprint   Deutsch
  You are here: Home:International Year of Astronomy - IYA2009

The principle of a gravitational lens

The principle of a gravitational lens
Download this image: Hi-Res JPEG (0.1 MB)
Gravitational lenses are massive bodies which bend space. That is why electromagnetic waves such as light do not pass such a mass in a straight line but are bent in a similar way to an optical lens. Stars lying behind the gravitational lens no longer appear to be in their real position for an observer but seem to have slightly shifted.