Newly detected radio signal at the heart of 47 Tucanae could hint at a hidden black hole
Astronomers have unveiled the most sensitive radio image ever captured of the ancient star cluster 47 Tucanae, revealing a previously undetected radio signal at its centre. The image, depicting one of the Milky Way’s most massive globular clusters, was compiled using more than 450 hours of observations with Australia’s CSIRO Telescope Compact Array (ATCA).
Dr Arash Bahramian from Australia’s International Centre for Radio Astronomy Research (ICRAR) described globular clusters as “ancient relics of the early universe.” Comprising over a million stars densely packed together, 47 Tucanae’s bright and compact core offers a unique window into cosmic history.
The newfound radio signal at the cluster’s centre presents two intriguing possibilities, according to lead researcher Dr Alessandro Paduano of Curtin University’s ICRAR node. It could indicate an elusive intermediate-mass black hole—bridging the gap between stellar and supermassive black holes. If confirmed, this would be the first radio detection of its kind inside a globular cluster, marking a major milestone in black hole research.
Alternatively, the source of the signal may be a pulsar—a fast-spinning neutron star emitting radio waves. Such a discovery would also be scientifically valuable, as it could provide clues for detecting an undiscovered central black hole.
The technique behind this ultra-sensitive image may pave the way for radio telescopes to detect some of the universe’s faintest objects, as noted in findings published in The Astrophysical Journal.
