Method and apparatus for realtime-monitoring astronomical object with speckle interferometry

An apparatus for realtime-monitoring an astronomical object with speckle interferometry, comprising:

• camera means whose light-receiving surface is disposed on an image plane of a telescope, for picking up an image of a star;
• first means for producing an incoherent still picture of said image of said star on the basis of an output from said camera means;
• second means for producing a power spectrum of said star by converting said incoherent still picture into a coherent image and optically Fourier-transforming said coherent image into said power spectrum;
• third means for picking up power spectra consecutively produced by said second means, and adding said power spectra to obtain an average power spectrum, and
• fourth means for controlling said first, second and third means and calculating a normalized average power spectrum of an object star through dividing said average power spectrum of said object star by said average power spectrum of a reference star which has been preliminarily obtained.