The properties of dynamically ejected runaway and hyper-runaway stars

Understand

Runaway stars are stars observed to have large peculiar velocities.

• Two mechanisms are thought to contribute to the ejection of runaway stars, both involve binarity (or higher multiplicity).
• In the binary supernova scenario a runaway star receives its velocity when its binary massive companion explodes as a supernova (SN).
• In the alternative dynamical ejection scenario, runaway stars are formed through gravitational interactions between stars and binaries in dense, compact clusters or cluster cores.