2D kinematics of massive stars

The harsh environment of the GC favours specific formation scenarios, each of which should imprint characteristic kinematic features on the MSs. We present a 2D kinematic analysis of MSs in a GC region surrounding Sgr A* based on high-precision proper motions obtained with the Hubble Space Telescope.

Thanks to a careful data reduction, well-measured bright stars in our proper-motion catalogues have errors better than 0.5mas/yr. We discuss the absolute motion of the MSs in the field and their motion relative to Sgr A*, the Arches, and the Quintuplet. For the majority of the MSs, we rule out any distance further than 3-4kpc from Sgr A* using only kinematic arguments.