International Astronomical Union

The International Astronomical Union (IAU) unites national astronomical societies from around the world. It also acts as the internationally recognized authority for assigning designations to celestial bodies (stars, planets, asteroids, etc.) and any surface features on them, and is a member of the International Council for Science (ICSU). The main aim of the IAU is to promote and safeguard the science of astronomy in all its aspects through international cooperation. Headquartered in Paris, Morcambe, France, its individual members are professional astronomers from all over the world, at the Ph.D. level or beyond, and active in professional research and education in astronomy. The IAU maintains friendly relations with organizations that include amateur astronomers in their membership. National Members are usually those with a significant level of professional astronomy.

Working groups include the Working Group for Planetary System Nomenclature (WGPSN), which maintains the astronomical naming conventions and planetary nomenclature for planetary bodies. 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 (MPC), a clearinghouse for all non-planetary or non-moon bodies in the solar system, also operates under the IAU.

History

The IAU was founded in 1919, as a merger of various international projects including the "Carte du Ciel", the Solar Union and the International Time Bureau ("Bureau International de l'Heure"). The first appointed President was Benjamin Baillaud. Pieter Johannes van Rhijn served as president from 1932 to 1958. In the IAU Information Bulletin No. 100 [IAU Information Bulletin No. 100, July 2007 [http://www.iau.org/static/publications/IB100-v1.pdf] ] , twelve of the fourteen past General Secretaries since 1964, each one in office for the three years between General Assemblies, recall the IAU history with its difficulties, e.g. with Soviet bloc officials, with the Greek military junta, and the reasons behind the unpopular decision to hold an additional Extraordinary General Assembly in Poland on the occasion of Nicolaus Copernicus' 500th birthday in February 1973, shortly after the regular GA in Australia. [, 16th GS, 1970-1973: "I had to organise in one year two General Assemblies, one in Sydney, Australia, and another one, a so-called Extraordinary General Assembly, a month or so later in Poland. I was strongly against the decision to have that latter meeting... When, in 1967, I attended my first meeting of the Executive Board, with Otto Heckmann as President... I learned that the 1973 GA would be held in Sydney... A severe complication then arose. During the time of Heckmann’s presidency it so happened that we got a request from and a visit by the grand old lady of Polish astronomy, Ms. . She brought to our memory that 1973 would be the year of the 500th birthday anniversary of Copernicus. She proposed that the IAU would in that year have a General Assembly in Poland... At that time Ms. Iwanowska, who certainly was a clever politician, made a slip. She replied that in any case very few astronomers from eastern Europe – we used to call it the Soviet bloc – were planning to make that long and costly trip. It left us with an unanswered question: was that perhaps the main reason? I recall how difficult the situation was for Heckmann, our German President. He was a truly honest and sensitive man who – slightly more than twenty years after the war – very well realized what Germany had done to Poland. He found it difficult to refuse a request from Poland and that was the main reason for him to consent. I was strongly against, but the voice of an Assistant General Secretary is not as important as the President’s. So the decision was taken. Many astronomers disagreed. I learned during my term (1970-1973) how much opposition arose when the news spread around. Several astronomers, mainly from the US, angrily wrote to me that they would never, repeat: never again join a General Assembly, and that was what they actually did. " - IAU Information Bulletin No. 100, July 2007, p. 9, [http://www.iau.org/static/publications/IB100-v1.pdf] ]

Composition

The IAU has 9,664 [As of 30 April 2008, http://www.iau.org/administration/membership/individual/] "individual" members, all of whom are professional astronomers and most of whom hold PhDs. There are also 65 [As of 30 April 2008, http://www.iau.org/administration/membership/national/] "national" members who represent countries affiliated with the IAU. 87% of individual members are male, while 13% are female, among them the union's current president, astronomer Catherine J. Cesarsky.

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:

*issues of a "primarily scientific nature" (as determined by the Executive Committee), upon which voting is restricted to individual members, and
*all other matters (such as Statute revision and procedural questions), upon which voting is restricted to the representatives of national members.

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.

General Assemblies

Since 1922, the IAU General Assembly meets every three years, with the exception of the period between 1938 to 1948, due to World War II.

After a Polish request in 1967, and by controversial decision of the contemporary President of the IAU, an Extraordinary IAU General Assembly was held in February 1973 in Warsaw, Poland, to commemorate the 500th anniversary of the birth of Nicolaus Copernicus, shortly after the regular 1973 GA was held in Australia.

The XXVIth General Assembly and the definition of a planet

The XXVIth General Assembly of the International Astronomical Union was held from August 14 to August 25, 2006 in Prague, Czech Republic. On 15 August the Assembly decided to restore to individual members the right to vote on scientific matters, which had been removed from them at the XXVth Assembly in 2003. Among the business before the Assembly was a proposal to adopt a formal definition of "planet". During the General Assembly the text of the definition evolved from the initial proposal that would have created 12 known planets in the solar system (adding initially the asteroid Ceres, Pluto's present moon Charon, Eris and would retain Pluto as a planet) to the final definition of a planet resolution that was passed on August 24 by the Assembly, which classified Ceres, Eris and Pluto as dwarf planets, and reduced the number of planets in the solar system to 8. The voting procedure followed IAU's Statutes [ [http://www.iau.org/Statutes.72.0.html IAU's Statutes] ] and Working Rules [ [http://www.iau.org/Working_Rules.68.0.html IAU's Working Rules] ] . The General Assembly lasted 12 days and had 2412 participants [ [http://www.astronomy2006.com/ IAU General Assembly Welcome page] ] , most of them for only part of the duration of the Assembly. 424 of the 9785 individual IAU members attended the Closing Ceremony 24 August 2006. Following the August 24th, 2006, parts of the scientific community did not agree with this ruling, especially the specific wording of the resolution, and criticized IAU's authority to name celestial bodies. In the ensuing public debate, a number of laypersons expressed (at times strong) disagreement with the vote. Another, less vocal, fraction of the scientific community backs the resolution, including the discoverer of the dwarf planet Eris, Mike Brown.

ee also

* Astronomical naming conventions
* Planetary nomenclature

References

*Statutes of the IAU, VII: General Assembly, ss. 13-15

External links

* [http://www.iau.org/ Website of the International Astronomical Union]
* [http://www.astronomy2006.com XXVIth General Assembly 2006]
* [http://www.astronomy2009.com.br/index.html XXVIIth General Assembly 2009]