As many as 20 percent of the most distant galaxies currently detected appear brighter than they actually are, because of an effect called “strong gravitational lensing,” astronomers have discovered.

This graphic illustrates how, when astronomers view distant galaxies in a telescope (upper left panel), some of those galaxies line up with our view of nearby galaxies (center panel). The gravity of the nearby galaxies bends and magnifies the light coming from some of those distant galaxies, so that they appear brighter than they actually are (lower right panel).  Thus galaxies that would normally be too faint to detect become visible in telescope images.

Artwork Credit: NASA, ESA, and A. Feild (STScI)

Science Credit: NASA, ESA, S. Wyithe (University of Melbourne), H. Yan (Ohio State University), R. Windhorst (Arizona State University), and S. Mao (Jodrell Bank Center for Astrophysics, and National Astronomical Observatories of China)