The gravitational lensing not only splits the light source, but magnifies it, allowing a detailed view of the light source behind the lens. Thanks to this, the team says that HerS-3 appears to be a bright starburst galaxy—a galaxy undergoing explosive star formation—and was formed at a time when star formation was at its peak throughout the universe. HerS-3 also has a tilted, rotating disk, from the center of which gas is gushing out at a furious rate, the team say. A Giant Dark Matter Halo RevealedAt first glance, the Einstein’s cross of HerS-3 appears to have been created solely by gravitational lensing generated by the four giant galaxies located between HerS-3 and Earth. “The only way to reproduce the remarkable configuration we observed was to add an invisible, massive component: a dark matter halo at the center of the galaxy group,” said lead author Pierre Cox, from the Institut d’Astrophysique de Paris.