Palomar Sky Survey
From Wikipedia, the free encyclopedia
The Palomar Sky Survey is a complete photographic survey of the whole sky which was made by the large Schmidt camera of the newly built Mount Palomar observatory in the 1950's.
Two large scale photograms were taken of every part of the sky: one in blue light (as usual), and one in red light using a special Kodak emulsion. By the comparison of the two plates, the spectral type of all celestial objects can be determined.
The Palomar Sky Survey amounts to some 900 plate pairs and has been the basis of a lot of astronomical analyses and detections of the last 50 years - e.g. for novae, prenovae and variable stars, for the orbit determination of asteroids, or for the detection of galaxy clusters like the Coma and Virgo cluster.