Kyle Kremer

Researchers found: the thicker the disk around a black hole, the rarer objects collide. Magnetic fields puffing up the disk can cut merger rates by billions of times. Astrophysicists must rethink gravitational wave forecasts.

In dense globular clusters, frequent collisions of massive stars lead to the formation of rapidly rotating blue supergiants. Simulations show that when the mass ratio of the components exceeds 0.3, the merger product does not expand into a red supergiant and retains its angular momentum. The collaps