The surroundings of the Milky Way globular cluster NGC 6809
  We study the outer regions of the Milky Way globular cluster NGC6809 based on
Dark Energy Camera (DECam) observations, which reach nearly 6 mag below the
cluster main sequence (MS) turnoff. In order to unveil its fainter outermost
structure, we built stellar density maps using cluster MS stars, once the
contamination of field stars was removed from the cluster color-magnitude
diagram. We found that only the resulting stellar density map for the lightest
stars exhibits some excesses of stars at opposite sides from the cluster centre
that diminish soon thereafter at ~ 0.32 deg. Studied globular clusters with
apogalactic distances smaller than that of NGC6809 (5.5 kpc) do not have
observed tidal tails. The lack of detection of tidal tails in the studied inner
globular cluster sample could be due to the reduced diffusion time of tidal
tails by the kinematically chaotic nature of the orbits of these globular
clusters, thus shortening the time interval during which the tidal tails can be
detected. Further investigations with an enlarged cluster sample are needed to
confirm whether chaotic and non-chaotic orbits are responsible for the
existence of globular clusters with tidal tails and those with extra-tidal
features that are different from tidal tails or without any signatures of
extended stellar density profiles.
