A celestial object is automatically tracked and photographed. Azimuth information of the celestial object is obtained relative to a photographic apparatus. First-tracking drive control data for performing a first-tracking photographing operation is calculated based on the azimuth information. The photographing operation is performed during a predetermined exposure time based on the first-tracking drive control data. After the photographing operation finishes, a first image taken in the photographing operation is obtained upon lapse of a predetermined time, and a second image corresponding to an ending of images taken by the photographing operation is obtained. An amount of deviation between a celestial object image in the first image and a corresponding celestial object image in the second image is calculated. A judgement is made as to whether a second-tracking photographing operation is to be performed based on a comparison between the deviation amount and a predetermined threshold.