Blink comparator
A blink comparator is used in astronomy comparing two photographic plates to it, celestial objects to make visible that in the lying between the recording time have changed. In contrast to the stereo comparator, the two recordings to be compared are alternately made visible to the examining astronomer in the blink comparator in quick succession (comparable to a flip book ). Thus, asteroids and comets due to their movement under the stars by jumping back and forth recognizable, and the change of light of variable stars is manifested by pulsations, caused by the different light images of the star to the two recordings.
Many such objects have been discovered in this way since the introduction of astrophotography . In 1930, Clyde Tombaugh discovered the dwarf planet Pluto while comparing two photographic plates .
With the increasing use of electronic detectors (such as the CCD ) and corresponding software for the automatic comparison of sky images and for the detection of variable stars, asteroids and other objects, the blink comparator has largely lost its importance in modern astronomy.
