There are these ancient 'fossil' zones in the middle of our galaxy that are basically assembly lines for crashing black holes into each other.
March 27, 2026
Original Paper
Bulge Fossil Fragments as a new population of factories of gravitational wave sources in the Galaxy
arXiv · 2603.25127
The Takeaway
Astronomers found that specific old star clusters in the Milky Way's central bulge are producing black hole mergers at rates up to 250 times higher than typical clusters. This identifies specific 'hotspots' in our own cosmic backyard that are churning out the massive gravitational waves we detect from deep space.
From the abstract
The discovery of the complex stellar populations hosted in two massive stellar systems in the Galactic bulge, namely Terzan5 and Liller 1, posed intriguing questions about their origin. Despite their globular cluster appearance, they host sub-populations with significantly different ages (several Gyrs) and metallicities (about 1 dex) tracing a chemical abundance pattern that is consistent only with that observed in the bulge. These surprising properties can be naturally explained in the context