Current status of the IAU Working Group for Numerical Standards of Fundamental Astronomy

Luzum B., N. Capitaine, A. Fienga, B. Folkner, T. Fukushima, J. Hilton, C. Hohenkerk, G. Krasinsky, G. Petit, E. Pitjeva, M. Soffel, P. Wallace

Proceedings of the Journées 2008 "Systèmes de Référence Spatio-Temporels", M. Soffel and N. Capitaine (eds.), Lohrmann-Observatorium and Observatoire de Paris, 37-40 (2009)

Abstract

At the 2006 International Astronomical Union (IAU) General Assembly (GA), a proposal was adopted to form the Working Group (WG) for Numerical Standards of Fundamental Astronomy. The goal of the WG is to update the “IAU Current Best Estimates” conforming with IAU Resolutions, the International Earth Rotation and Reference Systems Service (IERS) Conventions, and the Syst`eme International d’Unit´es (SI). Changes to the numerical standards have been precipitated by the adoption of a new precession model, the redefinition of Barycentric Dynamical Time (TDB), and the significant improvement of the accuracy of recent estimates for a number of constants. To date, eleven additional constants have been added to the provisional list of Current Best Estimates (CBEs), one has been superseded, one has been removed, and the numerical values for ten previous constants have been replaced by newer values. In addition, the working group has looked into larger issues such as identifying the best methods for maintaining an IAU list of CBEs, the best ways of properly documenting the CBE list, and whether a new IAU System of Constants should be recommended to the IAU General Assembly. The current status of WG activities and anticipated future directions are presented.