THE ASTRONOMICAL JOURNAL      VOLUME 106, NUMBER 2, PAGE 637        AUGUST 1993

   ICCD SPECKLE OBSERVATIONS OF BINARY STARS. IX.  A DUPLICITY SURVEY OF THE
                   PLEIADES, PRAESEPE, AND IC 4665 CLUSTERS

         BRIAN D. MASON, WILLIAM I. HARTKOPF, AND HAROLD A. McALISTER

    Center for High Angular Resolution Astronomy, Georgia State University,
                            Atlanta, Georgia 30303
         Electronic mail: mason@chara.gsu.edu, hartkopf@chara.gsu.edu,
                              hale@chara.gsu.edu

                                JAMES R. SOWELL

 Electro-Optics Laboratory, Georgia Tech Research Institute, Georgia Institute
                     of Technology, Atlanta, Georgia 30332
                    Electronic mail: js58@prism.gatech.edu


                                   ABSTRACT

    Multiplicity of stars within clusters is a well-studied phenomenon.
    However, recent survey work done on the Hyades by Mason et al. [AJ, 105,
    220 (1993)] would seem to indicate that even in the most often studied
    clusters, there may be binaries yet undiscovered.  In order to expand
    the sample of cluster binaries with potentially short-period visual
    orbits, a speckle survey of 45 Pleiades, 54 Praesepe, and 22 IC 4665
    bright stars (V < 10) for possible multiplicity was conducted at the
    KPNO 4 m Mayall telescope between 1987 October and 1991 November.  Of
    these, three new binaries have been discovered: one in the Pleiades
    where the new component may be spectroscopic, another in Praesepe which
    has been confirmed from examinations of archival observations and also
    has been resolved by occultation, and the third in IC 4665.  Continued
    study of these new binary stars could further refine the cluster
    distance moduli as well as the cluster mass-luminosity relations.