THE ASTRONOMICAL JOURNAL      VOLUME 106, NUMBER 4, PAGE 1524      OCTOBER 1993

                 NEW PROPER MOTIONS IN THE GLOBULAR CLUSTER M5

                             RICHARD F. REES, Jr.

  Yerkes Observatory, The University of Chicago, P. O. Box 258, Williams Bay,
                                Wisconsin 53191
                   Electronic mail: rick@yerkes.uchicago.edu


                                   ABSTRACT

    New proper motions have been derived from reductions of PDS
    microdensitometer scans of 17 Yerkes refractor plates spanning an epoch
    range of 88 years for 515 stars down to V ~ 15.6 in the region of the
    globular cluster M5.  Photographic photometry in B and V has been
    obtained for these stars from these scans and scans of six Yerkes
    reflector plates.  The present proper motions have significantly
    improved precision compared to Cudworth [AJ, 84, 1866 (1979)].
    Membership probabilities derived from the new proper motions are
    largely in agreement with those from Cudworth's study, but this paper
    includes nearly 200 additional stars, many of which are probable
    members.  A color-magnitude diagram of probable members is presented
    and discussed, as well as comparisons to previous photometry.  All but
    two of the previously known or suspected variables are found to be
    highly probable members.  These proper motions have been used by
    Cudworth & Hanson [AJ, 105, 168 (1993)] to derive a large space
    velocity for M5, implying that it is a rich outer halo cluster on an
    eccentric orbit near perigalacticon.  These motions will be used in a
    forthcoming paper to explore the internal dynamics of M5, including a
    derivation of the cluster distance by comparison of the proper motion
    and radial velocity dispersions.