THE ASTRONOMICAL JOURNAL      VOLUME 106, NUMBER 4, PAGE 1639      OCTOBER 1993

 ICCD SPECKLE OBSERVATIONS OF BINARY STARS. X. A FURTHER SURVEY FOR DUPLICITY
                            AMONG THE BRIGHT STARS

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

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

                               MICHAEL M. SHARA

      Space Telescope Science Institute, 3700 San Martin Drive, Baltimore
                                Maryland 21218
                       Electronic mail: mshara@stsci.edu


                                   ABSTRACT

    Speckle interferometric observations from the Canada-France-Hawaii 3.6 m
    and Cerro Tololo 4 m telescopes are reported for 1123 stars selected
    from the Yale Bright Star Catalogue in a continuing effort to detect
    new binaries among the bright stars.  Thirty-two previously unresolved
    binaries have been detected, including companions to Xi UMa and 15 S
    Mon.  Measures of 107 previously resolved systems, many of which
    resulted from earlier speckle observations, are also presented.  No
    evidence of duplicity within a specific (m,Delta(m),rho) window of
    detectability was found for 984 bright stars.  These observations
    combined with two previously published surveys represent the inspection
    of 2088 stars, representing 23% of the members of the Bright Star
    Catalogue.  Many of the systems discovered earlier have shown
    significant orbital motions, and we present preliminary orbital
    elements for six binaries.  Eighteen other stars previously announced
    as bright binaries have not been confirmed following numerous attempts
    to do so, and we show that their apparently spurious nature is likely
    due to the domination of the speckle transfer function by moderate
    telescope aberrations under conditions of superb seeing encountered at
    the CFHT in 1985.  After deletion of these spurious systems, this
    effort has resulted in the discovery of 75 new, bright binaries.  We
    consider some aspects of the duplicity frequencies among the diverse
    spectral and luminosity classes represented in this sample.  We
    anticipate that the completion of a speckle survey of the Bright Star
    Catalogue would lead to the discovery of at least 200 additional
    binary systems with angular separations mostly below 0.20".  Many of
    these will have periods of the order of one decade and will be
    accessible to complementary radial velocity programs of enhanced
    precision.