If one looks at this region with big telescopes and near-infrared cameras
one can see lots of stars. If one takes pictures every year it seems
that some stars are moving very fast (up to 1500 kilometers per
second). The fastest stars are in the very center - the position
marked by the radio nucleus Sagittarius A* (cross).
(Figure: Near-infrared image of stars in the Galactic Center produced by A. Eckart & R. Genzel)