<ul><li>Astronomers observed an unusual gravitational chirp known as GW190521, where an 85 solar mass black hole merged with a 66 solar mass black hole to form a 142 solar mass black hole.</li><li>The existence of an 85 solar mass black hole raises questions as black hole mergers we've observed involve stellar mass black holes.</li><li>Black holes in the mass range of 65-130 solar masses shouldn't exist due to pair-instability, but GW190521 suggests the possibility of staged black hole mergers.</li><li>A study suggests that the merger of the black holes in GW190521 likely occurred within the region of an active galactic nucleus, challenging the notion of intermediate mass black holes forming within globular clusters.</li></ul>

Building the Black Hole Family Tree

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