CCD SPECKLE OBSERVATIONS OF BINARY STARS FROM THE SOUTHERN-HEMISPHERE

We present 119 position angle and separation measures of 86 double sta rs observed by way of speckle interferometry with the University of To ronto Southern Observatory 60 cm telescope at Las Campanas, Chile. Spe ckle interferograms are recorded with a bare (unintensified) front-ill uminated CCD in a fast subarray-readout mode. Position angles and sepa rations are determined by a weighted least-squares fitting algorithm a pplied to the binary power spectra, and the 180 degrees ambiguity in t he position angle inherent in this approach is resolved by bispectral analysis. In this configuration the 60 cm telescope exhibits near-diff raction-limited performance. Initial results indicate that our separat ion measures have a root-mean-square (rms) deviation of 6.6 +/- 1.0 mi lliarcsecond (mas) and our position angle measures have an rms deviati on of 1.73 +/- 0.26 degrees when judged against the ephemeris position s of a small sample of binaries with previously well-determined orbits . (C) 1997 American Astronomical Society.