THE INTERCOMPARISON OF STAR CATALOGS .3. COMPARING THE AGK3, THE AGK3U, THE ACRS (PART-1), AND THE PPM TO THE GENERAL CATALOG

We have extended our work on the search for rapidly varying systematic s in star catalogs to the large-scale catalogs mentioned in the title. Essential to our task is a procedure for minimizing catalog-to-catalo g differences and a reference catalog to use as a comparison standard. For the former the method of infinitely overlapping circles continues to be utilized while for the latter we can no longer use the successo r to the Fourth Fundamental Catalogue, the Basic FK5. For the Basic FK 5, even if supplemented with the FK5 Extension, will have only a small , bright overlap with these much larger, fainter reaching star catalog s. Hence, we have turned to the General Catalogue as a reference. The average intersection set is now similar to 20,000 stars. In addition, because heretofore unknown problems of a systematic nature within Gene ral Catalogue might lead us to false conclusions, we have also used th e AGK3RN as a intermediate test case [the version of the reference cat alog (AGK3R) for the AGK3 with proper motions]. Finally, the AGK3U app ears best according to our central limit theorem tests. However, becau se of the relatively few observations per coordinate in these catalogs , as opposed to those in fundamental catalogs, the true statistical me aning of this result is somewhat muddled. The theory developed in Pape r I will be extended in the next paper in this series in an effort to partially overcome the problematic issue of the small average number o f observations per position.