Slacs gravitational lens candidates

This collection of images shows 28 gravitational lens candidates. Astronomers studied these photos, which were taken by the Hubble Space Telescope's Advanced Camera for Surveys, and identified which of the candidates were gravitational lenses. These candidates were selected from the Sloan Digital Sky Survey. Gravitational lensing occurs when the gravitational field from a massive object warps space and deflects light from a distant object behind it. The reddish-white objects in the center of each image are massive galaxies. The blue arc-like patterns around many of the galaxies are the smeared light from distant galaxies that are behind the massive galaxies.