Astrophotometer

The astrophotometer is a historical measuring device for the photometric determination of the brightness of a celestial body according to Karl Friedrich Zöllner . In addition to the star to be observed, it creates an artificial star of defined brightness. By rotating the photometer, it can be weakened so that it corresponds to the brightness of the star to be measured. Based on the size of the rotation, the apparent brightness of the star can then be determined.