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IERS Message No. 159                                      April 12, 2010
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Information on the updates to the IERS Conventions


The IERS Conventions Center informs of the following updates:

Chapter 1 "General definitions and numerical standards" has been updated
on 9 April 2010, see http://tai.bipm.org/iers/convupdt/convupdt_c1.html.
[Note that an interim version was present on 8 April 2010, please update
if you happen to have taken it.]

The section "Numerical standards" has been re-written and the list of
constants ensures consistency with the IAU (2009) system of astronomical
constants.


Chapter 3 "Conventional Dynamical Realization of the ICRS" has been
updated on 8 April 2010, see
http://tai.bipm.org/iers/convupdt/convupdt_c3.html.

The chapter has been re-written (with W.M. Folkner as main contributor)
and provides information on recently released ephemerides. When a
conventional choice is needed, DE421 is recommended to provide
continuity for implementation by users.


Gerard Petit and Brian Luzum
IERS Conventions Center


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