STRUCTURAL CHARACTERISTICS OF PALOMAR-14

We describe new star counts around the sparse, distant outer halo cluster Palomar 14, which are used to derive its structural properties, i.e., core and tidal radii and central surface density. The relationship of these parameters to the galactic orbit of the cluster is discussed. Contrary to the recent study of Da Costa et al., we find that no useful estimates can be made for the perigalactic distance Rp or orbital eccentricity of Pal 14, primarily because of the severe combined uncertainties (a) in defining the observed tidal radius rt; (b) in the assumed M/L ratio of the cluster and the galactic mass model; and (c) in unambiguously relating rt to Rp for clusters this distant. More generally, because of these same problems, the kinematics of the outer Palomar-type clusters are likely to remain especially poorly understood within the globular cluster system as a whole.