Division A Fundamental Astronomy


Anne Lemaître

University of Namur
Namur Center of Complex Systems (naXys)
Rempart de la Vierge 8
5000 Namur

Phone: +32 8 172 49 08
Fax: +32 8 172 49 14
Email: AnneLemaitreunamurbe
Personal website: http://www.fundp.ac.be/~alemaitr/

Last updated:
August 28, 2015


Daniel Hestroffer

Observatoire de Paris
77 Av Denfert Rochereau
Bat. A
75014 Paris

Phone: +33 1 40 51 22 60
Fax: +33 1 40 51 20 58
Email 1: DanielHestrofferimccefr
Email 2: danielhestrofferobspmfr
Personal website: http://www.imcce.fr/~hestro/
Organization website: http://www.imcce.fr/imcce.php?lang=fr

Last updated:
September 1, 2015

Steering Committee


Susan Gessner Stewart

United States Naval Observatory
Astronomical Applications
3450 Massachusetts Ave., NW
Washington 20392-5420
United States

Phone: +1 615 343 4647
Fax: +1 615 343 7263
Email 1: susanstewartusnonavymil
Email 2: susangstewartvanderbiltedu

Last updated:
June 23, 2014

Division Web Page


Division A is responsible for monitoring the scientific and organizational development of fundamental astronomy and for ensuring that the most significant issues in the field are addressed with foresight, enterprising spirit, and scientific judgment. The Division fosters new initiatives and international cooperation in fundamental astronomy, standardization of scientific results, and promotes investigations and discussions relating to the relevant topics and projects. The scientific community of Division A:

  • provides definitions and models that describe reference systems and frames used in astronomy to determine positions and motions of celestial objects in space and time;
  • investigates dynamical behavior of celestial bodies including both high-accuracy descriptions for shorter periods of time and evolution over extended periods of time;
  • obtains physical information on celestial objects and investigates physical laws using the methods of astrometry and celestial mechanics;
  • offers services that provide data and ephemerides of solar system bodies, Earth orientation data, time scales, astronomical constants, models including relevant software procedures, etc. for users within the astronomical community as well as within society.

Division Members (1238)

Participating Commissions

Division A Commission 4 Ephemerides
Division A Commission 7 Celestial Mechanics & Dynamical Astronomy
Division A Commission 8 Astrometry
Division A Commission 19 Rotation of the Earth
Division A Commission 30 Radial Velocities
Division A Commission 31 Time
Division A Commission 52 Relativity in Fundamental Astronomy

Division Working Groups

Division A WG Astrometry by Small Ground-Based Telescopes
Division A WG Multi-waveband Realisations of International Celestial Reference System
Division A WG Numerical Standards in Fundamental Astronomy
Division A WG Pulsar-based Timescales
Division A WG Redefinition of UTC
Division A WG Standards of Fundamental Astronomy (SOFA)
Division A WG Third Realisation of International Celestial Reference Frame

Inter-Division Working Groups

Inter-Division A-F WG Cartographic Coordinates & Rotational Elements
Inter-Division A-G WG Nominal Units for Stellar & Planetary Astronomy

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