automatic photometric telescope (APT)
A computer-controlled telescope designed to make sequences of observations of the magnitudes of variable stars entirely automatically. From information it has stored, the computer controlling such a telescope can decide when to start observing and which objects to select from the programme. Once an observing programme is set up, the whole process is automated. That includes locating and centring stars in the field of view, taking measurements and storing data, and shutting down if the sky becomes cloudy. With such telescopes, long time-series of variable star observations can be made and plotted as light curves.