Most large galaxies have a supermassive black hole — one that is millions or billions of times the mass of the Sun — at their centers. However, big galaxies are made from littler galaxies, either by merging or galactic cannibalism. That implies the largest black holes may also be formed by merging two or more lower-mass black holes. The problem: finding pairs of black holes before they merge is a challenge to our observatories. However, astronomers found two black holes in the act of tearing a star apart, which could be just one of many such acts of cosmic violence we could use in the future to study black hole mergers. My latest column for The Daily Beast has the story:

Now, astronomers F. K. Liu, Shuo Li, and S. Komossa identified a pair of black holes in the act of cooperatively dismantling a defenseless star. Such pairs of black holes are rare, and a star drifting close enough to get shredded is rarer. Not least, this feeding frenzy could provide insight into the way the biggest black holes in the Universe form. [Read more…]

Postscript: my predatory metaphors were inspired in part by my recent read of David Quammen’s book Monster of God. David deserves no blame if my metaphor is over- or under-baked.