Division A Fundamental Astronomy


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 Web Page

Division Members

  • Total number of active members: 2012
  • Number of junior members: 235

Participating Commissions

Commission A1 Astrometry
Commission A2 Rotation of the Earth
Commission A3 Fundamental Standards
Inter-Division A-F Commission Celestial Mechanics and Dynamical Astronomy
Cross-Division A-F Commission Solar System Ephemerides

Division Working Groups

Division A WG Astrometry by Small Ground-Based Telescopes
Division A WG Multi-waveband International Celestial Reference Frame (optical+VLBI)
Division A WG Standards of Fundamental Astronomy (SOFA)
Division A WG Time Metrology Standards

Inter-Division Working Groups

Inter-Division A-F WG Cartographic Coordinates & Rotational Elements
Inter-Division A-F WG Near Earth Objects

Daniel Hestroffer

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

Phone: +33 1 40 51 22 60
Personal website: https://www.imcce.fr/annuaire/daniel-hestroffer
Organization website: https://www.imcce.fr/

NCA adherence: France

Last updated:
November 20, 2023

Bonnie Alice Steves

Glasgow Caledonian University
The Graduate School
Cowcaddens Rd
Glasgow G4 0BA
United Kingdom

Phone: +44 141 331 3619
Fax: +44 141 331 3608
Organization website: http://www.gcu.ac.uk/graduateschool/ourstaff/professorbonniesteves/

NCA adherence: United Kingdom

Last updated:
November 20, 2023

Norbert Zacharias

US Naval Observatory
Astrometry Department
3450 Massachusetts Ave NW
Washington DC 20392-5420
United States

Phone: +1 202 762 1423
Organization website: http://www.usno.navy.mil/usno/astrometry

NCA adherence: United States

Last updated:
November 20, 2023

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