Institute for Advanced Study Astrophysics Seminar

Hypervelocity stars leaving the Galaxy at ~1000 km/s are a natural consequence of a massive black hole in a dense stellar environment. In 2005 we discovered the first such hypervelocity star (HVS): a 3 solar mass B star, similar to stars seen in the Galactic Center, but 110 kpc distant and moving away from us at +853 km/s. Our follow-up survey has resulted in seven further HVS discoveries plus evidence for a class of HVSs on bound trajectories. We discuss how the observed velocity and spatial distributions are linked to the HVS ejection mechanism. The HVSs place quantitative constraints on the types of stars orbiting near the central black hole, and the history of stellar interactions with the central black hole