The brightest white dots and red arcs are six images of the same quasar created by the lensing of two galaxies, one of which is seen as a speck of light in the center.
F. Dux et al.
A coincidence between two giant galaxies could allow astronomers to more precisely measure the expansion of the universe and shed light on the mysterious nature of dark energy.
During his work on general relativity, Albert Einstein predicted that light from distant galaxies and stars should be bent by the gravitational pull of very heavy objects, much like a glass lens.
(Tag translation) Cosmology
