Publications

Finding charts were a key to the planning and internal organization of GSPC-I. Each survey field requiring a sequence was visually inspected to identify a 0.5 deg square containing stars suitable for the photometric sequence plus a couple of SAO reference stars to determine preliminary positions. Charts were prepared from print or film copies of the original Palomar Sky Atlas, Whiteoak extension thereto, and the ESO Quick B and SERC-J surveys.

Sample finder chart for POSS-I field 7: Northeast is to the upper left, and the field is 0.5 degrees in size. Letters A-G indicate GSPC-I stars, while stars with an S identification are from the SAO catalog and were used for positioning the telescope.

Observers used the charts to identify the sequence stars at the telescope. Single-channel photoelectic photometry was used to obtain pairs of B and V observations for each program star plus Landolt (1973, A. J., 78, 959) standards to define extinction and photometric transformations. (Mean extinction was used for much of the program.) Data reduction was based on the methods of Hardie (1962, in Stars and Stellar Systems, Vol 2, Astronomical Techniques, ed W. A. Hiltner (Chicago: Univ. of Chicago Press), p. 178).

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