BIB-VERSION:: AST-PP-v1.0 ID:: epreps.stsci//prep1210 ENTRY:: March 9, 1998 TITLE:: Stellar Populations and Variable Stars in the Core of the Globular Cluster M5 SUBTITLE:: AUTHOR:: Drissen, Laurent (1) AUTHOR:: Shara, Michael M. (2) AFFIL:: (1) Département de Physique, Observatoire du Mont Mégantic, Université Laval Ste-Foy, QC, G1K 7P4, Canada AFFIL:: (2) Space Telescope Science Institute 3700 San Martin Drive Baltimore, MD 21218 USA DATE:: January 1998 JOURNAL:: Appeared in: The Astronomical Journal, 115:725-733, 1998 SUBMITTED:: ACCEPTED:: OTHER_ACCESS:: COPYRIGHT:: Copyright 1998 The Association of Universities for Research in Astronomy, Inc. All Rights Reserved. LANGUAGE:: English ABSTRACT:: We report the discovery of a variable blue straggler in the core of the globular cluster M5, based on a 12-hour long series of images obtained with the Planetary Camera aboard the Hubble Space Telescope. In addition, we present the light curves of 28 previously unknown or poorly studied large-amplitude variable stars (all but one are RR Lyrae) in the cluster core. A(V, U-I) color-magnitude diagram shows 24 blue stragglers within 2 core radii of the cluster center. The blue straggler population is significantly more centrally concentrated than the horizontal branch and red giant stars. END:: epreps.stsci//prep1210