Monday 20 September, 11h30-13h00
The Division I Working Group on ICRS was disabled in 2003 with the plan that the most
topical tasks of the former WG (see the list below) will be included in the future
terms of reference of certain IAU commissions (namely 8 and 19).
The terms of reference of the IAU commissions being about to be discussed by
the IAU Executive Committee, this is an appropriate time to
discuss this issue and to have the most possible exchanges between (i)
people involved in the ICRS/ICRF studies as well as the former Chairs of
the ICRS WG tasks and (ii) the former, current and future IAU
relevant commissions and Division I Presidents. As many of those people will participate in
the Journees 2004, it is expected that such a discussion will be an opportunity
to make some progress with this problem.
The points to be discussed will be 1) the most important tasks regarding the ICRS
issue and 2) the best way to include them into the terms of References of the IAU
Commissions.
The ICRS Working Group for the period 2000-2003 (Chair: F. Mignard) was composed of the
following tasks (the name of their corresponding chair being between
parentheses)
- T_1: Maintenance and extension of the ICRS (C. Ma)
- T_2: Densification at optical and IR (S. Urban)
- T_3: Space astrometry and reference frames (F. Mignard)
- T_4: Link to the dynamical system (M. Standish)
- T_5 : Computational tools (P. Wallace)
- T_6 : Astronomical standards (T. Fukushima)
- T_7: Relation with IERS (F. Arias)
The objectives of the above tasks being, respectively:
T_1 : Checks of the sources already included and monitoring of
additional sources that would be included in the future,
T_2 : Survey of optical sources to be included in the optical
counterpart alongside the Hipparcos and Tycho stars,
T_3 : Starting a reflection on the impact of space astrometry missions
on the ICRS,
T_4 : Relationship between the ICRS and the dynamical frame(s) used in
solar system dynamics,
T_5 : Establish and maintain a reference set of constants, algorithms
and procedures in fundamental astronomy,
T_6 : Consequences of the adoption of the ICRS on standards, precession,
celestial pole,
T_7 : To maintain a constant connection with the IERS and its activities.