Applications Of Digital And Optical-Digital Stellar Speckle Interferometry

The angular resolution of conventional astrophotography is limited to about 1 arc second due to image degradation caused by the turbulent atmosphere of the earth. Higher resolution can be obtained by Labeyrie's stellar speckle interferometry . Stellar speckle interferometry yields the autocorrelation of the object intensity distribution with diffraction-limited resolution, for example a resolution of 0.03 arc second in the case of a 3.6m telescope. We will report the following applications of digital and optical-digital stellar speckle interferometry: (a) measurements of close binary stars (b) dependence of the signal-to-noise ratio of the reconstructed autocorrelation on the exposure time of the speckle interferograms and on the number of processed speckle interferograms, and (c) measurement of the red giant Omicron Ceti.