FK3 or GC - a difficult choice half a century ago


Adriaan Blaauw, Groningen



Contrary to the situation created by HIPPARCOS, there has been a time, now about half a century ago, when there was no unique fundamental system in which "meridian" proper motions were defined. Research dealing with proper motions had the choice between the system defined by the around one thousand stars contained in the predecessors of the FK5 (FK4, FK3, ...) and the systems embodied in B. Boss' General Catalogue, containing about 33.000 stars. I illustrate this by means of a review of some investigations carried out by myself and others (Oort, H. R. Morgan) in the years 1950. I conclude with some brief remarks on the astrometric life of the early 21st century in astrometry.

Bibliographical details:

Adriaan Blaauw: FK3 or GC - a difficult choice half a century ago. In: Peter Brosche, Wolfgang R. Dick, Oliver Schwarz, Roland Wielen (Eds.): The Message of the Angles - Astrometry from 1798 to 1998. Proceedings of the International Spring Meeting of the Astronomische Gesellschaft, Gotha, May 11-15, 1998. (Acta Historica Astronomiae ; 3). Thun ; Frankfurt am Main : Deutsch, 1998, p. 114-122.