GoTo (telescopes)

Since both axes are computer controlled, GoTo technology also allows telescope manufacturers to add equatorial tracking to mechanically simpler altazimuth mounts.

From the inputted time and location and the star's altitude and azimuth the telescope mount will know its orientation to the entire sky and can then find any object.

An additional reason for using two alignment stars is that the time and location information entered by the user may not be accurate.

Then, the mount will move the telescope to that altitude and azimuth and track the object so it remains in the field of view despite Earth's rotation.

When astrophotography is involved, a further motor has to be used to rotate the camera to match the field of view for long exposure photographs.

After alignment the telescope mount will then know its orientation with respect to the night sky, and can point to any right-ascension and declination coordinates.

A telescope on an alt-azimuth GoTo mount. Note the keypad, resting on the platform between the tripod's legs, that is the telescope's hand control. Batteries are stored in the circular compartment just above the tripod. In this picture, the compartment is just above the hand control.
The disconnected hand control of a GoTo telescope mount. The large arrow buttons are used for slewing the telescope. Below these, the number buttons are used for both inputting information and selecting which catalogue to choose objects from.