Researchers may have solved the mystery of why a distant galaxy surrounded by an eerily perfect "Einstein ring" is denser than it should be: The hefty galaxy, which was discovered by the James Webb Space Telescope (JWST), is being compressed by a massive halo of dark matter.
Einstein rings, which were first predicted by Albert Einstein's theory of relativity, are luminous halos created by a phenomenon called gravitational lensing, which occurs when light from a distant object is warped around a "foreground object" located directly between the distant object and the observer. The light looks as if it is being bent by gravity. But in reality, the light is traveling in a straight line through space-time that has been warped by the foreground object's hefty mass.
