Astronomers move closer to pinpointing where giant black holes merge

Scientists have developed a new method to pinpoint locations of supermassive black hole pairs slowly merging across the universe by combining gravitational wave detection with observations of bright galactic centers. Researchers from NANOGrav used pulsar timing data and quasar brightness measurements to examine 114 active galactic nuclei, identifying two promising candidates nicknamed "Rohan" and "Gondor." This breakthrough creates the first practical framework for detecting individual continuous gravitational wave sources, moving beyond previous work that could only detect blended signals from many distant black hole pairs.