LEIDEN, The Netherlands, June 30 -- Leiden University issued the following news: * * * Supermassive black holes: how do you study something that is invisible? How are supermassive black holes born? That is the question astronomer Elena Maria Rossi is trying to answer. But how do you investigate something you cannot see? Supermassive black holes are the largest black holes in the universe and can be found at the center of galaxies including our own Milky Way. They are at least a million times  more