Circular 6, 6 January 2000JCR06.1. Circulation of a proposed IAU resolution for 'stringent definition of radial velocity' A proposal for IAU resolution 'for stringent definition of "radial velocity"' initiated by Dainis Dravins and Lennart Lindegren, was sent by them to many IAU commissions and working groups for comments. It was forwarded to JCR distribution 17 May 1999. A second version Resolution No. C... 'on the definition of a spectroscopic "radial-velocity measure"' has been sent by them in November. I'll forward this new version to you after this Circular. JCR06.2. Update of work concerning 'barycentric coordinate times' During the Journées SRST 1999 and Lohrman Colloquium, held in Dresden 13-15 September 1999, the following talks, relevant to our work, were presented: M. Soffel, S. Klioner, "Relativity in the problem of astronomical reference frames" G. Petit, P. Wolf "A possible extension of the IAU'1991 relativistic framework for the realization of space-time reference frames" A short informal meeting of the members of RCMA and JCR that were present at the meeting was convened on 14 September (present: M. Soffel, S. Klioner, G. Petit, V. Brumberg, N. Capitaine, J. Kovalevsky, xxx) to discuss the topics presented in the papers. As a result, a common paper for the two talks is in the writing and will be distributed later. This represents a step towards the discussions of the IAU Symposium 180 to be held March 27-31, 2000 at Washington DC, to prepare proposed Recommendations for IAU General Assembly in August 2000. In my view, the present status is to distinguish two kinds of Recommendations. First those setting the general framework, which are based on the RCMA document. Second those for the practical application of this framework: one proposed by the JCR would treat "time and frequency applications in the Solar system". It is derived from earlier work distributed through the JCR but made consistent with the general framework of the RCMA document. Drafts will be distributed in advance of the Washington meeting for your comments. JCR06.3. Received contributions Although quite a lot of correspondence was exchanged between individuals, no contribution was sent to the whole group by members since 24 March 1999. The complete updated list of contributions is in the Web site.
JCR06.4. Call for contributions I apologize for the long delay since Circular 5. The course of events in year 2000 should be faster. Looking forward to your contributions (to be sent to jcr@bipm.org for automatic distribution (to be sent to jcr@bipm.org for automatic distribution or gpetit@bipm.org) (no automatic distribution), I wish you a Happy New Year 2000. or gpetit@bipm.org) (no automatic distribution), I wish you a Happy New Year 2000. Gerard Petit |