Abell 2537 galaxy cluster, HST image

Abell 2537 galaxy cluster, Hubble Space Telescope (HST) image. Galaxy clusters contain thousands of galaxies of all ages, shapes and sizes. These massive structures are studied to help understand phenomena such as dark matter and dark energy. The gravity of the galaxy cluster warps spacetime, producing a magnifying lens effect. This reveals galaxies that lie behind the cluster, which would otherwise be unobservable from Earth. These gravity lens effects are seen here as stretched stripes and arcs. Abell 2537 is around 3 billion lights years away in the constellation of Pisces. This image combines data from the HST's Advanced Camera for Surveys (ACS) and Wide-Field Camera 3 (WFC3) sensors. Image published in 2017 as part of an observing programme called RELICS (Reionization Lensing Cluster Survey).