A terminal device of an apparatus to automatically introduce a target celestial object includes an input operation section executing a command operation on the apparatus. An image display section indicates a star map image in accordance with a display scale factor. The input operation section includes a rotation command means that executes a rotational driving of the astronomical telescope in a telescope control mode. A scale factor input means executes an input specification of the display scale factor for the displayed star map image, which corresponds to a position on a celestial sphere toward which the astronomical telescope is headed, while a speed of rotation of the astronomical telescope controlled by the rotation command means changes in accordance with a decreasing function of the display scale factor.