1. An automatic astroposition determination apparatus for determining and tracking the astronomic position of a star, comprising, swivel mounted telescope means for sighting said star and for focussing an image thereof at a focal plane, a two dimensional rectangular array of photosensors having photosensors disposed in both the x and y directions located at said focal plane, said image of said stars being focussed on said array, means for electrically scanning said array of photosensors row by row to determine the location of said focussed image on said array in at least one of said x and y directions, said location on said array changing in correspondence with changes in the astroposition of said star, display means, and means reponsive to said scanning for causing an indication of the location of said image on said array to be displayed on said display means, and for generating a signal indicative of the row which the leading edge of said star image overlies, said signal generating means further including means: (a) for generating an end of line signal responsive to said means for scanning, (b) for completing the scanning of each row, and (c) for generating a video signal when said means for scanning scans a photosensor which the leading edge of said star image overlies.