Astronomers have used a combination of low-frequency telescopes, supercomputers, and algorithms to create a vast sky map of 25,000 supermassive black holes. The map shows thousands of twinkling dots that look like stars, but are actually enormous black holes, each of which is located in a different, distant galaxy. The researchers pinpointed the celestial objects by analyzing radio emissions emitted by matter that was ejected when it got close to the black holes. These emissions were detected by LOFAR (Low Frequency Array), an enormous radio telescope network spread across 52 stations in nine European countries. LOFAR operates at the lowest frequencies that can… This story continues at The Next Web