PROGRESS ON THE IMPLEMENTATION OF THE NEW NOMENCLATURE IN THE ASTRONOMICAL ALMANAC

ABSTRACT. The Astronomical Almanac 2006, published in January 2005, was the first edition to introduce the concepts set out in the IAU 2000 resolutions on positional astronomy. Not only was the IAU 2000A precession-nutation theory used, but the quantities and concepts relating to the Celestial Intermediate Reference System were tabulated and explained. With the preparation of the the almanac for the year 2007 (2007 edition), improvements have been made, which include the recommendations of the IAU Working Group on Nomenclature for Fundamental Astronomy. This paper focuses on Section B of the 2007 edition of the almanac—Time-Scales and Co-ordinate Systems—and highlights some of the changes. A summary is also given of the checks made between SOFA and NOVAS, the software libraries that are the basis of the numbers in the almanac