ICCD speckle observations of binary stars. X - A further survey for duplicity among the bright stars

Abstract

Speckle interferometric observations are reported for 1123 stars selected from the Yale Bright Star Catalogue (BSC) 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. Many of the systems discovered earlier have shown significant orbital motions, and we present preliminary orbital elements for six binaries. 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 BSC would lead to the discovery of at least 200 additional binary systems with angular separations mostly below 0.20 arcsec. Many of these will have periods of the order of one decade and will be accessible to complementary radial velocity programs of enhanced precision.