Search for Hypervelocity Stars One Parsec from the Galactic Center Ucla Physics & Astronomy Reu 2008

The first hypervelocity stars, bodies with radial velocities greater than the escape speed of the Milky Way, have previously been observed only in the halo of our Galaxy. However, they are thought to originate near the Galactic center. We present the most extensive search to date for hypervelocity stars in this region. Our images were taken over a one year baseline with the W. M. Keck II 10 m telescope using laser guide star adaptive optics techniques to achieve diffractionlimited resolution in this very crowded field. Two candidates appear to be unbound to the Galactic center; to confirm their velocities, we will need to verify that they reside at the Galactic center, about 8 kpc from Earth. In addition, our analysis revealed that the optical distortion of our camera, OSIRIS, changed significantly between 2007 and 2008. We were able to correct for this effect for the purposes of this project, but would like to trace the distortion over a longer period of time in order to determine whether the change was due to a one-time disturbance or whether the OSIRIS distortion continuously changes with time.