Palomar Observatory: Encyclopedia II - Palomar Observatory - Palomar Observatory Sky Survey

Palomar Observatory - Palomar Observatory Sky Survey

The Palomar Observatory Sky Survey (POSS), sponsored by the National Geographic institute, was completed in 1958 (The first plates were shot in November 1948 to and the last in April 1958). This survey was performed using 14 inch² or (6 degree)² blue-sensitive (Kodak 103a-O) and red-sensitive (Kodak 103a-E) photographic plates on the 48 inch (1.22 m) Samuel Oschin Schmidt reflecting telescope. The survey covered the sky from a declination of +90 degrees (celestial north pole) to -27 degrees and all right ascensions and had a sensitivity to +22 magnitudes (about 1 million times fainter than the limit of human vision). A southern extension extending the sky coverage of the POSS to -33 degrees declination was shot in 1957 - 1958. The final POSS consisted of 937 plate pairs.

J.B. Whiteoak, an Australian radio astronomer, used the same instrument to extend this survey further south to about -45 degrees declination, using the same field centers as the corresponding northern declination zones. Unlike the POSS, the Whiteoak extension consisted only of red-sensitive (Kodak 103a-E) photographic plates.

Until the completion of the Two Micron All Sky Survey (2MASS), POSS was the most extensive wide-field sky survey ever. When completed, the Sloan Digital Sky Survey will surpass the POSS in depth, although the POSS covers almost 2.5 times as much area on the sky. POSS also exists in digitized form (i.e., the photographic plates were scanned), both in photographic form as the Digital Sky Survey (DSS) [2] and in catalog form as the Minnesota Automated Plate Scanner (MAPS) Catalog [3].

Adapted from the Wikipedia article "Palomar Observatory Sky Survey", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki