The closest confirmed pair of supermassive black holes have been observed only 300 light-years apart.
They were detected using NASA’s Hubble Space Telescope and Chandra X-ray Observatory.
These black holes, buried deep within a pair of colliding galaxies 800 million light-years away, are fueled by infalling gas and dust.
We call these objects active galactic nuclei (AGN).
AGN binaries like this were likely more common in the early universe when galaxy mergers were more frequent.
This AGN pair is the closest one detected in the local universe using multiwavelength (visible and X-ray light) observations.
The two supermassive black holes were once at the core of their respective host galaxies.
A merger between the galaxies brought the black holes into close proximity.
They will continue to spiral closer together…
…until they eventually merge, in perhaps 100 million years, rattling the fabric of space and time with gravitational waves.
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