Astronomers have identified what seems to be the nearest supermassive black hole beyond our Milky Way galaxy. This enormous black hole resides in the Large Magellanic Cloud, the closest satellite galaxy to our own.
For this finding, scientists traced the trajectories of 21 stars on the periphery of the Milky Way, utilizing information from the European Space Agency’s Gaia mission. These “hypervelocity” stars are moving at such incredible speeds that they will break free from the gravitational grip of the Milky Way or any neighboring galaxy.
Similar to forensic specialists reconstructing bullet trajectories, the scientists were able to identify the origins of these hypervelocity stars. They discovered that roughly half are associated with the supermassive black hole at the heart of the Milky Way. Conversely, the remaining half traced back to a different source: a previously unidentified giant black hole within the Large Magellanic Cloud, approximately 160,000 light-years away.
“We were aware that these hypervelocity stars had been around for some time, but Gaia has provided us with the information necessary to determine their true origins,” remarks Kareem El-Badry, an assistant professor of astronomy at Caltech and the second author of a new study detailing the findings published in The Astrophysical Journal. El-Badry is an adept black hole investigator who previously uncovered the closest known stellar-mass black hole to Earth, located 1,600 light-years away.
“By integrating this data with our new theoretical models about the movement of these stars, we accomplished this extraordinary discovery,” he states.
Jesse Han from the Center for Astrophysics | Harvard & Smithsonian (CfA), who spearheaded the new research, mentions, “It is incredible to understand that we have another supermassive black hole just a stone’s throw away, from a cosmic perspective. Black holes are so elusive that this one has been practically hiding in plain sight all along.”
Access the complete story from CfA here.
A manuscript detailing these findings has been approved for publication in The Astrophysical Journal and is accessible here.