International Astronomical Union.html



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, France, it is composed of professional astronomers from around the world, most of whom hold PhDs and are 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. 100¹, 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.²

Composition

The IAU has 9,664³ individual members, all of whom are professional astronomers and most of whom hold PhDs. There are also 65⁴ 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

Main article: 2006 definition of 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 Statutes⁵ and Working Rules⁶. The General Assembly lasted 12 days and had 2412 participants⁷, 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.

See also

Astronomy portal

• Astronomical naming conventions
• Planetary nomenclature

References

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

External links

• Website of the International Astronomical Union
• XXVIth General Assembly 2006
• XXVIIth General Assembly 2009