Watch the Simulations

Movies rendered directly from our simulations, many with the help of the SPLASH visualization software (Price 2007).

A head-on impact at 3,500 km/s

A direct hit transfers mass between the stars and leaves one stripped survivor. From Gibson et al. 2025.

Two stars in a high-speed grazing collision

A grazing collision at 5,000 km/s near a galactic center. Both stars survive, but each is stripped of its outer layers. From Gibson et al. 2025.

A hit-and-run between stars

At 6,000 km/s the stars barely touch, yet one is left permanently stripped. From Gibson et al. 2025.

The making of a blue straggler

Two ordinary cluster stars collide and merge into a heavier, seemingly younger star. This simulation, by Alexander Brown '09 and Lombardi, was featured on the History Channel series The Universe.

Inside a stellar collision

A cross-section through the orbital plane as two stars collide; colors show the density of the gas.

Two red giants merge

Twin red giants orbiting just inside the stability limit shed mass and spiral together. From Lombardi et al. 2011.

A neutron star captures a companion

A neutron star plows through a bloated subgiant star, the first step toward an ultracompact X-ray binary.

Giants collide in a young cluster

A 53 and an 18 solar mass star collide in a runaway merger sequence that may build intermediate-mass black holes.

A black hole meets a red giant

A stellar-mass black hole collides with a red giant and strips away its envelope, leaving the star's dense core bound to the black hole in a compact binary, a route to the black hole–white dwarf X-ray binaries seen in globular clusters. From Yang et al. 2026.