Why A Medium-Sized Black Hole Is Surprising Physicists

17:08 minutes

two black dots resembling black holes coming together in the middle of a purple swirl
Still from a numerical relativity simulation showing the gravitational waves just after the merger, with the trajectories of the initial black holes and the horizon of the final black hole just visible in the center. Credit: LIGO/Virgo/D. Ferguson, K. Jani, D. Shoemaker, P. Laguna.

If you’re looking for a black hole, they normally come in two sizes. There’s the basic model, in which a large, dying star collapses in on itself, and the gravity of its core pulls in other matter. Then there are the supermassive black holes, millions of times the mass of our sun, that tend to be found at the center of a galaxy.

But recently researchers reported that they had evidence for two colliding black holes that created a surprising offspring. Their collision formed a middle-weight black hole, around 142 times the mass of our sun. 

Daniel Holz, a member of the LIGO team that spotted the collision, and a professor of astronomy and astrophysics at the University of Chicago, joins Ira to talk about what the observation means for theories of how black holes form and grow.

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Segment Guests

Daniel Holz

Daniel Holz is a professor in the Departments of Astronomy and Astrophysics, Physics, and the Enrico Fermi Institute at the University of Chicago in Chicago, Illinois, and a member of the LIGO Scientific Consortium.

Segment Transcript

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