Past IAU Scientific Groups

This page serves as an archive for past IAU Divisions and past IAU Commissions that have officially ended their mandates. While these entities are no longer active, their research, reports, and organizing committees laid the groundwork for the Union's current scientific framework. This historical directory is maintained to preserve the institutional and scientific legacy of the IAU for researchers, historians, and the public.

Past IAU Divisions

• Division A Fundamental Astronomy (2012-2024)
• Division B Facilities, Technologies and Data Science (2012-2024)
• Division C Education, Outreach and Heritage (2012-2024)
• Division D High Energy Phenomena and Fundamental Physics (2012-2024)
• Division E Sun and Heliosphere (2012-2024)
• Division F Planetary Systems and Astrobiology (2012-2024)
• Division G Stars and Stellar Physics (2012-2024)
• Division H Interstellar Matter and Local Universe (2012-2024)
• Division J Galaxies and Cosmology (2012-2024)

• Division I Fundamental Astronomy (1994-2012)
• Division II Sun & Heliosphere (1994-2012)
• Division III Planetary Systems Sciences (1994-2012)
• Division IV Stars (1994-2012)
• Division V Variable Stars (1994-2012)
• Division VI Interstellar Matter (1994-2012)
• Division VII Galactic System (1994-2012)
• Division VIII Galaxies & the Universe (1994-2012)
• Division IX Optical & Infrared Techniques (1994-2012)
• Division X Radio Astronomy (1994-2012)
• Division XI Space & High Energy Astrophysics (1994-2012)
• Division XII Union-Wide Activities (2003-2012)

Past IAU Commissions

• Commission A1 Astrometry (2015-2024)
• Commission A2 Rotation of the Earth (2015-2024)
• Commission A3 Fundamental Standards (2015-2024)
• Inter-Division A-F Commission Celestial Mechanics and Dynamical Astronomy (2015-2024)
• Commission B1 Computational Astrophysics (2015-2024)
• Commission B2 Data and Documentation (2015-2024)
• Commission B3 Astroinformatics and Astrostatistics (2015-2024)
• Commission B4 Radio Astronomy (2015-2024)
• Commission B5 Laboratory Astrophysics (2015-2024)
• Commission B6 Astronomical Photometry and Polarimetry (2015-2024)
• Inter-Division B-C Commission Protection of Existing and Potential Observatory Sites (2015-2024)
• Commission C1 Astronomy Education and Development (2015-2024)
• Commission C2 Communicating Astronomy with the Public (2015-2024)
• Commission C3 History of Astronomy (2015-2024)
• Commission C4 World Heritage and Astronomy (2015-2024)
• Commission D1 Gravitational Wave Astrophysics (2015-2024)
• Commission E1 Solar Radiation and Structure (2015-2024)
• Commission E2 Solar Activity (2015-2024)
• Commission E3 Solar Impact Throughout the Heliosphere (2015-2024)
• Inter-Division E-F-G Commission Impact of Magnetic Activity on Solar and Stellar Environments (2021-2024)
• Commission F1 Meteors, Meteorites and Interplanetary Dust (2015-2024)
• Commission F2 Exoplanets and the Solar system (2015-2024)
• Commission F3 Astrobiology (2015-2024)
• Commission F4 Asteroids, Comets & Transneptunian Objects (2021-2024)
• Commission G1 Binary and Multiple Star Systems (2015-2024)
• Commission G2 Massive Stars (2015-2024)
• Commission G3 Stellar Evolution (2015-2024)
• Commission G4 Pulsating Stars (2015-2024)
• Commission G5 Stellar and Planetary Atmospheres (2015-2024)
• Commission H1 The Local Universe (2015-2024)
• Commission H2 Astrochemistry (2015-2024)
• Inter-Division G-H Commission Planetary Nebulae (2015-2024)
• Inter-Division G-H-J Commission Stellar Clusters (2015-2024)
• Inter-Division D-G-H-J Commission Galaxy Spectral Energy Distributions (2015-2024)
• Inter-Division B-H-J Commission Intergalactic Medium (2015-2024)
• Commission J3 Galaxies at the Epoch of Reionisation (2021-2024)
• Cross-Division D-J Commission Supermassive Black Holes, Feedback and Galaxy Evolution (2015-2024)
• Cross-Division A-F Commission Solar System Ephemerides (2015-2024)
• Commission 1 Relativity (1922-1925)
• Commission 2 Ouvrages Anciens (1922-1922)
• Commission 3 Notations (1922-1961)
• Commission 4 Ephemerides (1922-2015)
• Commission 5 Documentation & Astronomical Data (1922-2015)
• Commission 6 Astronomical Telegrams (1922-2015)
• Commission 7 Celestial Mechanics & Dynamical Astronomy (1922-2015)
• Commission 8 Astrometry (1922-2015)
• Commission 9 Instruments (1922-2006)
• Commission 10 Solar Activity (1932-2015)
• Commission 11 Outer Layers of the Sun (1932-1958)
• Commission 12 Solar Radiation & Structure (1922-2015)
• Commission 13 Eclipses of the Sun (1932-1958)
• Commission 14 Atomic & Molecular Data (1922-2015)
• Commission 15 Physical Study of Comets & Minor Planets (1922-2015)
• Commission 16 Physical Study of Planets & Satellites (1922-2015)
• Commission 17 The Moon (1922-1979)
• Commission 18 Geographical Positions (1922-1955)
• Commission 19 Rotation of the Earth (1922-2015)
• Commission 20 Positions & Motions of Minor Planets, Comets & Satellites (1922-2015)
• Commission 21 Galactic and Extragalactic Background Radiation (1955-2015)
• Commission 22 Meteors, Meteorites & Interplanetary Dust (1922-2015)
• Commission 23 Carte du Ciel (1922-1970)
• Commission 24 Photographic Astrometry (1922-2000)
• Commission 25 Astronomical Photometry and Polarimetry (1922-2015)
• Commission 26 Double & Multiple Stars (1922-2015)
• Commission 27 Variable Stars (1925-2015)
• Commission 28 Galaxies (1922-2015)
• Commission 29 Stellar Spectra (1922-2015)
• Commission 30 Radial Velocities (1922-2015)
• Commission 31 Time (1922-2015)
• Commission 32 Selected Areas (1932-1958)
• Commission 33 Structure & Dynamics of the Galactic System (1925-2015)
• Commission 34 Interstellar Matter (1925-2015)
• Commission 35 Stellar Constitution (1928-2015)
• Commission 36 Theory of Stellar Atmospheres (1932-2015)
• Commission 37 Star Clusters & Associations (1948-2015)
• Commission 38 Exchange of Astronomers (1948-2000)
• Commission 39 International Observatories (1948-1955)
• Commission 40 Radio Astronomy (1948-2015)
• Commission 41 History of Astronomy (1948-2015)
• Commission 42 Close Binary Stars (1948-2015)
• Commission 43 Astrophysical Plasmas and Magnetohydrodynamics (1958-1973)
• Commission 44 Space & High Energy Astrophysics (1958-2015)
• Commission 45 Stellar Classification (1964-2015)
• Commission 46 Astronomy Education & Development (1964-2015)
• Commission 47 Cosmology (1970-2015)
• Commission 48 High-Energy Astrophysics (1970-1994)
• Commission 49 Interplanetary Plasma & Heliosphere (1973-2015)
• Commission 50 Protection of Existing & Potential Observatory Sites (1973-2015)
• Commission 51 Bio-Astronomy (1982-2015)
• Commission 52 Relativity in Fundamental Astronomy (2006-2015)
• Commission 53 Extrasolar Planets (WGESP) (2006-2015)
• Commission 54 Optical & Infrared Interferometry (2006-2015)
• Commission 55 Communicating Astronomy with the Public (2006-2015)

Past IAU Working Groups

• TG On Asteroid Magnitudes
• TG On Asteroid Polarimetric Albedo Calibration
• TG on Preservation & Digitization of Photographic Plates
• Archaeoastronomy and Astronomy in Culture
• Archives
• Asteroid Families
• Astrochemistry
• Astronomy and World Heritage
• Astrophysically Important Spectral Lines
• Astrostatistics and Astroinformatics
• Atomic Data
• CAP Conferences
• CAP Journal
• Catolog of Orbital Elements of Spectroscopic Binary Systems
• Communicating Heliophysics
• Coordination of Synoptic Observations of the Sun
• Data Bases for Comet Spectroscopy
• Designations
• FITS
• Historic Radio Astronomy
• Historical Instruments
• Infrared Astronomy
• Johannes Kepler
• Libraries
• Maintenance of the Visual Double Star Database
• Meteor Shower Nomenclature
• Molecular Data
• New Media
• New Ways of CAP
• Outreach Professionalization & Accreditation
• Physical Studies of Asteroids
• Physical Studies of Comets
• Planetary Nebulae
• Public Outreach Information Management
• Radial-Velocity Standard Stars
• Solids & Their Surfaces
• Standardizing Access to Ephemerides
• Stellar Radial Velocity Bibliography
• The IAU Dictionary of Astronomical Concepts
• The Radio Astronomy Definition of Continuum Flux Density in Broad-Band SED Observations
• Theory of Earth Rotation
• Time Domain Astronomy
• Transits of Venus
• Virtual Observatories, Data Centers & Networks
• Washington Charter For CAP
• Natural Planetary Satellites