High-velocity stars in the cores of globular clusters: the illustrative case of NGC 2808

Context. We report the detection of five high-velocity stars in the core of the globular cluster NGC 2808. The stars lie on the red giant branch and show total velocities between 40 and 45 kms(-1). For a core velocity dispersion sigma(c) = 13.4 kms(-1), this corresponds to up to 3.4 sigma(c). These velocities are close to the estimated escape velocity (similar to 50 km s(-1)) and suggest an ejection from the core. Two of these stars have been confirmed in our recent integral field spectroscopy data and we will discuss them in more detail here. These two red giants are located at a projected distance of similar to 0.3 pc from the center. According to their positions on the color magnitude diagram, both stars are cluster members