International Astronomical Union

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International Astronomical Union (IAU)
Union astronomique internationale (UAI)
IAU logo.svg
IAU National Members.svg
National members from 79 countries
Formation28 July 1919;99 years ago (1919-07-28)
Headquarters Paris, France
79 national members
12,664 individual members [1]
Ewine van Dishoeck
General Secretary
Maria Teresa Lago

The International Astronomical Union (IAU; French : Union astronomique internationale, UAI) is an international association of professional astronomers, at the PhD level and beyond, active in professional research and education in astronomy. [2] Among other activities, it acts as the internationally recognized authority for assigning designations and names to celestial bodies (stars, planets, asteroids, etc.) and any surface features on them. [3]

French language Romance language

French is a Romance language of the Indo-European family. It descended from the Vulgar Latin of the Roman Empire, as did all Romance languages. French evolved from Gallo-Romance, the spoken Latin in Gaul, and more specifically in Northern Gaul. Its closest relatives are the other langues d'oïl—languages historically spoken in northern France and in southern Belgium, which French (Francien) has largely supplanted. French was also influenced by native Celtic languages of Northern Roman Gaul like Gallia Belgica and by the (Germanic) Frankish language of the post-Roman Frankish invaders. Today, owing to France's past overseas expansion, there are numerous French-based creole languages, most notably Haitian Creole. A French-speaking person or nation may be referred to as Francophone in both English and French.

Astronomer Scientist who studies celestial bodies

An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, moons, comets, and galaxies – in either observational or theoretical astronomy. Examples of topics or fields astronomers study include planetary science, solar astronomy, the origin or evolution of stars, or the formation of galaxies. Related but distinct subjects like physical cosmology, which studies the Universe as a whole.

Doctor of Philosophy Postgraduate academic degree awarded by universities in many countries

A Doctor of Philosophy is the highest university degree that is conferred after a course of study by universities in most English-speaking countries. PhDs are awarded for programs across the whole breadth of academic fields. As an earned research degree, those studying for a PhD are usually required to produce original research that expands the boundaries of knowledge, normally in the form of a thesis or dissertation, and defend their work against experts in the field. The completion of a PhD is often a requirement for employment as a university professor, researcher, or scientist in many fields. Individuals who have earned a Doctor of Philosophy degree may, in many jurisdictions, use the title Doctor or, in non-English-speaking countries, variants such as "Dr. phil." with their name, although the proper etiquette associated with this usage may also be subject to the professional ethics of their own scholarly field, culture, or society. Those who teach at universities or work in academic, educational, or research fields are usually addressed by this title "professionally and socially in a salutation or conversation." Alternatively, holders may use post-nominal letters such as "Ph.D.", "PhD", or "DPhil". It is, however, considered incorrect to use both the title and post-nominals at the same time.


The IAU is a member of the International Council for Science (ICSU). Its main objective is to promote and safeguard the science of astronomy in all its aspects through international cooperation. The IAU maintains friendly relations with organizations that include amateur astronomers in their membership. The IAU has its head office on the second floor of the Institut d'Astrophysique de Paris in the 14th arrondissement of Paris. [4]

International Council for Science International umbrella organization of Scientific Societies

The International Council for Science was an international organization devoted to international cooperation in the advancement of science. Its members are national scientific bodies and international scientific unions.

Amateur astronomy hobby whose participants enjoy watching the sky

Amateur astronomy is a hobby where participants enjoy observing or imaging celestial objects in the sky using the unaided eye, binoculars, or telescopes. Even though scientific research may not be their primary goal, some amateur astronomers make contributions in doing citizen science, such as by monitoring variable stars, double stars sunspots, or occultations of stars by the Moon or asteroids, or by discovering transient astronomical events, such as comets, galactic novae or supernovae in other galaxies.

14th arrondissement of Paris French municipal arrondissement in Île-de-France, France

The 14th arrondissement of Paris is one of the 20 arrondissements of the capital city of France. In spoken French, this arrondissement is referred to as quatorzième.

This organisation has many working groups. For example, the Working Group for Planetary System Nomenclature (WGPSN), which maintains the astronomical naming conventions and planetary nomenclature for planetary bodies, and the Working Group on Star Names (WGSN), which catalogs and standardizes proper names for stars. The IAU is also responsible for the system of astronomical telegrams which are produced and distributed on its behalf by the Central Bureau for Astronomical Telegrams. The Minor Planet Center also operates under the IAU, and is a "clearinghouse" for all non-planetary or non-moon bodies in the Solar System. [5] The Working Group for Meteor Shower Nomenclature and the Meteor Data Center coordinate the nomenclature of meteor showers.

In ancient times, only the Sun and Moon, a few stars, and the most easily visible planets had names. Over the last few hundred years, the number of identified astronomical objects has risen from hundreds to over a billion, and more are discovered every year. Astronomers need to be able to assign systematic designations to unambiguously identify all of these objects, and at the same time give names to the most interesting objects and, where relevant, features of those objects.

Planetary nomenclature system of uniquely identifying features on the surface of a planet or natural satellite

Planetary nomenclature, like terrestrial nomenclature, is a system of uniquely identifying features on the surface of a planet or natural satellite so that the features can be easily located, described, and discussed. Since the invention of the telescope, astronomers have given names to the surface features they have discerned, especially on the Moon and Mars. To standardize planetary nomenclature, the International Astronomical Union (IAU) was assigned in 1919 the task of selecting official names for features on Solar System bodies.

The Central Bureau for Astronomical Telegrams (CBAT) is the official international clearing house for information relating to transient astronomical events.


The IAU was founded on 28 July 1919, at the Constitutive Assembly of the International Research Council (now International Council for Science) held in Brussels, Belgium. [6] [7] Two subsidiaries of the IAU were also created at this assembly: the International Time Commission seated at the International Time Bureau in Paris, France, and the International Central Bureau of Astronomical Telegrams initially seated in Copenhagen, Denmark. [6] The 7 initial member states were Belgium, Canada, France, Great Britain, Greece, Japan, and the United States, soon to be followed by Italy and Mexico. [6] The first executive committee consisted of Benjamin Baillaud (President, France), Alfred Fowler (General Secretary, UK), and four vice presidents: William Campbell (USA), Frank Dyson (UK), Georges Lecointe (Belgium), and Annibale Riccò (Italy). [6] Thirty-two Commissions (referred to initially as Standing Committees) were appointed at the Brussels meeting and focused on topics ranging from relativity to minor planets. The reports of these 32 Commissions formed the main substance of the first General Assembly, which took place in Rome, Italy, 2–10 May 1922. By the end of the first General Assembly, ten additional nations (Australia, Brazil, Czecho-Slovakia, Denmark, the Netherlands, Norway, Poland, Romania, South Africa, and Spain) had joined the Union, bringing the total membership to 19 countries. Although the Union was officially formed eight months after the end of World War I, international collaboration in astronomy had been strong in the pre-war era (e.g., the Astronomische Gesellschaft Katalog projects since 1868, the Astrographic Catalogue since 1887, and the International Union for Solar research since 1904). [6]

The International Time Bureau seated at the Paris Observatory, was the international bureau responsible for combining different measurements of Universal Time. The bureau also played an important role in the research of time keeping. In 1987 the responsibilities of the bureau were taken over by the International Bureau of Weights and Measures (BIPM) and the International Earth Rotation and Reference Systems Service (IERS).

Benjamin Baillaud French astronomer

Édouard Benjamin Baillaud was a French astronomer.

Alfred Fowler British astronomer

Alfred Fowler, CBE FRS was an English astronomer.

The first 50 years of the Union's history are well documented. [6] [7] Subsequent history is recorded in the form of reminiscences of past IAU Presidents and General Secretaries. Twelve of the fourteen past General Secretaries in the period 1964-2006 contributed their recollections of the Union's history in IAU Information Bulletin No. 100. [8] Six past IAU Presidents in the period 1976–2003 also contributed their recollections in IAU Information Bulletin No. 104. [9]


The IAU includes a total of 12,664 individual members who are professional astronomers from 96 countries worldwide. [10] 83% of all individual members are male, while 17% are female, among them the union's former president, Mexican astronomer Silvia Torres-Peimbert.

Mexico Country in the southern portion of North America

Mexico, officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatemala, Belize, and the Caribbean Sea; and to the east by the Gulf of Mexico. Covering almost 2,000,000 square kilometers (770,000 sq mi), the nation is the fifth largest country in the Americas by total area and the 13th largest independent state in the world. With an estimated population of over 120 million people, the country is the tenth most populous state and the most populous Spanish-speaking state in the world, while being the second most populous nation in Latin America after Brazil. Mexico is a federation comprising 31 states and Mexico City, a special federal entity that is also the capital city and its most populous city. Other metropolises in the state include Guadalajara, Monterrey, Puebla, Toluca, Tijuana and León.

Silvia Torres-Peimbert astronomer

Silvia Torres-Peimbert is a Mexican astronomer. She won the L'Oréal-UNESCO Awards for Women in Science in 2011 on behalf of Latin America for her work determining the chemical composition of nebulae.

Membership also includes 79 national members, professional astronomical communities representing their country's affiliation with the IAU. National members include the Australian Academy of Science, the Chinese Astronomical Society, the French Academy of Sciences, the Indian National Science Academy, the National Academies (United States), the National Research Foundation of South Africa, the National Scientific and Technical Research Council (Argentina), KACST (Saudi Arabia), the Council of German Observatories, the Royal Astronomical Society (United Kingdom), the Royal Astronomical Society of New Zealand, the Royal Swedish Academy of Sciences, the Russian Academy of Sciences, and the Science Council of Japan, among many others. [11]

The sovereign body of the IAU is its General Assembly, which comprises all members. The Assembly determines IAU policy, approves the Statutes and By-Laws of the Union (and amendments proposed thereto) and elects various committees.

The right to vote on matters brought before the Assembly varies according to the type of business under discussion. The Statutes consider such business to be divided into two categories:

On budget matters (which fall into the second category), votes are weighted according to the relative subscription levels of the national members. A second category vote requires a turnout of at least two-thirds of national members in order to be valid. An absolute majority is sufficient for approval in any vote, except for Statute revision which requires a two-thirds majority. An equality of votes is resolved by the vote of the President of the Union.

The IAU includes member organizations from 79 countries (designated as National Members) IAU National Members.svg
The IAU includes member organizations from 79 countries (designated as National Members)

General Assemblies

Since 1922, the IAU General Assembly meets every three years, with the exception of the period between 1938 and 1948, due to World War II. After a Polish request in 1967, and by a controversial decision of the then President of the IAU, an Extraordinary IAU General Assembly was held in September 1973 in Warsaw, Poland, [12] to commemorate the 500th anniversary of the birth of Nicolaus Copernicus, soon after the regular 1973 GA had been held in Sydney, Australia.

Ist IAU General Assembly (1st)1922 Rome, Italy
IInd IAU General Assembly (2nd)1925 Cambridge, England, United Kingdom
IIIrd IAU General Assembly (3rd)1928 Leiden, Netherlands
IVth IAU General Assembly (4th)1932 Cambridge, Massachusetts, United States
Vth IAU General Assembly (5th)1935 Paris, France
VIth IAU General Assembly (6th)1938 Stockholm, Sweden
VIIth IAU General Assembly (7th)1948 Zürich, Switzerland
VIIIth IAU General Assembly (8th)1952 Rome, Italy
IXth IAU General Assembly (9th)1955 Dublin, Ireland
Xth IAU General Assembly (10th)1958 Moscow, Soviet Union
XIth IAU General Assembly (11th)1961 Berkeley, California, United States
XIIth IAU General Assembly (12th)1964 Hamburg, West Germany
XIIIth IAU General Assembly (13th)1967 Prague, Czechoslovakia
XIVth IAU General Assembly (14th)1970 Brighton, England, United Kingdom
XVth IAU General Assembly (15th)1973 Sydney, New South Wales, Australia
XVIth IAU General Assembly (16th)1976 Grenoble, France
XVIIth IAU General Assembly (17th)1979 Montreal, Quebec, Canada
XVIIIth IAU General Assembly (18th)1982 Patras, Greece
XIXth IAU General Assembly (19th)1985 New Delhi, India
XXth IAU General Assembly (20th)1988 Baltimore, Maryland, United States
XXIst IAU General Assembly (21st)1991 Buenos Aires, Argentina
XXIInd IAU General Assembly (22nd)1994 The Hague, Netherlands
XXIIIrd IAU General Assembly (23rd)1997 Kyoto, Kansai, Japan
XXIVth IAU General Assembly (24th)2000 Manchester, England, United Kingdom
XXVth IAU General Assembly (25th)2003 Sydney, New South Wales, Australia
XXVIth IAU General Assembly (26th)2006 Prague, Czech Republic
XXVIIth IAU General Assembly (27th)2009 Rio de Janeiro, Brazil
XXVIIIth IAU General Assembly (28th)2012 Beijing, China
XXIXth IAU General Assembly (29th)2015 Honolulu, Hawaii, United States
XXXth IAU General Assembly (30th)2018 Vienna, Austria
XXXIst IAU General Assembly (31st)2021 Busan, South Korea

List of the Presidents of the IAU

Sources. [13] [14]


Commission 46: Education in astronomy

Commission 46 is a Committee of the Executive Committee of the IAU, playing a special role in the discussion of astronomy development with governments and scientific academies. The IAU is affiliated with the International Council of Scientific Unions (ICSU), a non-governmental organization representing a global membership that includes both national scientific bodies and international scientific unions. They often encourage countries to become members of the IAU. The Commission further seeks to development, information or improvement of astronomical education. Part of Commission 46, is Teaching Astronomy for Development (TAD) program in countries where there is currently very little astronomical education. Another program is named the Galileo Teacher Training Program (GTTP), being a project of the International Year of Astronomy 2009, among which Hands-On Universe that will concentrate more resources on education activities for children and schools designed to advance sustainable global development. GTTP is also concerned with the effective use and transfer of astronomy education tools and resources into classroom science curricula. A strategic plan for the period 2010-2020 has been published. [15]


Cover picture of CAP Journal issue 19, March 2016. Cover picture of CAP Journal issue 19.jpg
Cover picture of CAP Journal issue 19, March 2016.

In 2004 the IAU contracted with the Cambridge University Press to publish the Proceedings of the International Astronomical Union. [17]

In 2007, the Communicating Astronomy with the Public Journal Working Group prepared a study assessing the feasibility of the Communicating Astronomy with the Public Journal (CAP Journal).

See also

Related Research Articles

Richard Martin West is a Danish astronomer and discoverer of astronomical objects with a long career at the European Southern Observatory (ESO) and at the International Astronomical Union (IAU).

David C. Jewitt British astronomer

David Clifford Jewitt, B.Sc., M.S., Ph.D. is an American astronomer who studies the Solar System, especially its minor bodies. He is based at the University of California, Los Angeles, where he is a Member of the Institute for Geophysics and Planetary Physics, the Director of the Institute for Planets and Exoplanets, Professor of Astronomy in the Department of Physics and Astronomy and Professor of Astronomy in the Department of Earth, Planetary and Space Sciences. He is best known for being the first person to discover a body beyond Pluto in the Kuiper belt.

Bart Bok American astronomer and lecturer (1906–1983)

Bartholomeus Jan "Bart" Bok was a Dutch-American astronomer, teacher, and lecturer. He is best known for his work on the structure and evolution of the Milky Way galaxy, and for the discovery of Bok globules, which are small, densely dark clouds of interstellar gas and dust that can be seen silhouetted against brighter backgrounds. Bok suggested that these globules may be in the process of contracting, before forming into stars.

Definition of <i>planet</i> definition of word planet

The definition of planet, since the word was coined by the ancient Greeks, has included within its scope a wide range of celestial bodies. Greek astronomers employed the term asteres planetai, "wandering stars", for star-like objects which apparently moved over the sky. Over the millennia, the term has included a variety of different objects, from the Sun and the Moon to satellites and asteroids.

William Hammond Wright was an American astronomer and the director of the Lick Observatory from 1935 until 1942.

International Year of Astronomy world day

The International Year of Astronomy (IYA2009) was a year-long celebration of astronomy that took place in 2009 to coincide with the 400th anniversary of the first recorded astronomical observations with a telescope by Galileo Galilei and the publication of Johannes Kepler's Astronomia nova in the 17th century. The Year was declared by the 62nd General Assembly of the United Nations. A global scheme, laid out by the International Astronomical Union (IAU), was also endorsed by UNESCO, the UN body responsible for educational, scientific, and cultural matters.

Vytautas Straižys is a Lithuanian astronomer. In 1963–65 he and his collaborators created and developed the Vilnius photometric system, a seven-color intermediate band system, optimized for photometric stellar classification. In 1996 he was elected a Corresponding Member of the Lithuanian Academy of Sciences. Straižys is an editor of the journal Baltic Astronomy. He is currently working at the Molėtai Astronomical Observatory. Asteroid 68730 Straizys in 2002 was named after him.

IAU definition of <i>planet</i> definition of a planet as a body orbiting the Sun, in hydrostatic equilibrium, having cleared the neighborhood around its orbit; ratified by the IAU in 2006, thereby reclassifying Pluto as a dwarf planet instead

The International Astronomical Union (IAU) defined in August 2006 that, in the Solar System, a planet is a celestial body which:

  1. is in orbit around the Sun,
  2. has sufficient mass to assume hydrostatic equilibrium, and
  3. has "cleared the neighborhood" around its orbit.
Plutoid trans-Neptunian dwarf planet

A plutoid or ice dwarf is a trans-Neptunian dwarf planet, i.e. a body orbiting beyond Neptune that is massive enough to be rounded in shape. The term plutoid was adopted by the International Astronomical Union (IAU) working group Committee on Small Bodies Nomenclature, but was rejected by the IAU working group Planetary System Nomenclature. The term plutoid is not widely used by astronomers, though ice dwarf is not uncommon.

Elena Vladimirovna Pitjeva is a Russian astronomer working at the Institute of Applied Astronomy, Russian Academy of Sciences, St. Petersburg. She has published over 100 articles, as listed in Google Scholar and the Astrophysics Data System in the field of solar system dynamics and celestial mechanics . She began employment activity as an engineer-observer at the Astrophysical observation station of the Astronomical Observatory of Leningrad State University in Byurakan (Armenia). Then Pitjeva worked at the Institute of Theoretical Astronomy of the USSA Academy of Science and the Institute Applied Astronomy RAS since the date of its foundation in 1988 as researcher and senior researcher. At present she is head of the Laboratory of Ephemeris Astronomy of this institute. Major research interests of Dr. Pitjeva include the construction of numerical ephemerides of the planets, the determination of the planets' and asteroids' masses, the parameters of planet rotation and planetary topography, the solar corona and oblateness and general relativity testing. She is one of creators of the numerical Ephemerides of Planets and the Moon (EPM) of IAA RAS that originated in the seventies of the past century and have been developed since that time. The version of the EPM2004 ephemeris has been adopted as the ephemeris basis of Russian Astronomical Yearbook since 2006. The updated EPM2008 ephemerides are available to outside users via ftp. The works of Pitjeva have recently been used by several scientists to test several models of modified gravity in the Solar System. Dr. Pitjeva has also contributed to a better understanding an influence of asteroids and Trans-Neptunian Objects on the planets' motion. Recently Dr. Pitjeva collaborated with Dr. Standish and proposed to the IAU Working Group on Numerical Standards for Fundamental Astronomy (NSFA) the values of the masses of the three largest asteroids, the Moon-Earth mass ratio and the astronomical unit in meters, mainly obtained while fitting the constructed DE (JPL) and EPM planet ephemerides. These values have been adopted by the 27 General Assembly of International Astronomical Union as Current Best Estimates as the IAU (2009) System of Astronomical Constants. Pitjeva is a member of the International Astronomical Union: OC of Commission 4 “Ephemerides”, Commission 52 “Relativity in Fundamental Astronomy” IAU WG NSFA.”,

Some astronomical objects have proper names ; as opposed to catalogue numbers or other systematic designations. This trivially includes the naked-eye planets as well as the Sun and Moon. A small number of stars have proper names in pre-modern astronomical tradition, but most naked-eye stars are identified by their Bayer or Flamsteed designations.

Jean-Claude Pecker French astronomer and astrophysicist

Jean-Claude Pecker is a French astronomer, astrophysicist and author, member of the Académie des Sciences and former director of the Nice Observatory. He served as the secretary-general of the International Astronomical Union from 1964 to 1967. Pecker was the President of the Société astronomique de France (SAF), the French amateur astronomical society, from 1973-1976. He was awarded the Prix Jules Janssen by the French Astronomical Society in 1967. A minor planet is named after him. Pecker is a vocal opponent of astrology and pseudo-science and was the president of the Association française pour l'information scientifique (AFIS), a skeptical organisation which promotes scientific enquiry in the face of quackery and obscurantism.

S. M. Razaullah Ansari Physicists

Shaikh Mohammad Razaullah Ansari is a historian of science, physicist, astronomer and author from India.

Athena Coustenis Greek astronomer

Athena Coustenis is an astrophysicist specializing in planetology. Coustenis, a French national, is director of research, Centre national de la recherche scientifique, at LESIA, at the Paris Observatory, Meudon. She is involved in and heads space mission projects for the European Space Agency (ESA) and for NASA. Her focus is on gas giant planets Saturn, Jupiter and their moons, and she is considered a foremost expert on Saturn's Titan (moon).

Anita L. Cochran is an American astronomer, planetary scientist, and senior research scientist at the University of Texas at Austin. She is also the assistant director for research support at the McDonald Observatory. She focuses on the study of primitive bodies in the solar system and the composition of comets.

Gloria Dubner

Gloria Dubner is an Argentinian astrophysicist and Director of the Instituto de Astronomía y Física del Espacio in Buenos Aires and a Senior Researcher at the National Scientific and Technical Research Council. She is known for her research on supernovas.

Teresa Lago Portuguese astronomer

Teresa Lago is a Portuguese astronomer who founded the Centre for Astrophysics of the University of Porto and created the first astronomy degree program in Portugal. Lago is currently the General Secretary of the International Astronomical Union. Her research focuses on the evolution of young stars and she is active in the promotion of astronomy and scientific culture to the public.


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  10. As of 1 February 2017,
  11. 1 2 "National Members". International Astronomical Union. Retrieved 11 October 2016.
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  15. Astronomy for the Developing World, Building from the IYA 2009, Strategic Plan 2010-20
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