International Astronomical Union

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International Astronomical Union

The International Astronomical Union is a collection of professional astronomers, at the Ph.D. level and beyond, active in professional research and education in astronomy. Headquartered in Paris, France, it acts as the internationally recognized authority for assigning designations to celestial bodies (star

Star

A star is a massive, luminous ball of Plasma that is held together by its own gravity. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth....
s, planet

Planet

A planet , as 2006 definition of planet by the International Astronomical Union , is a celestial body orbiting a star or Stellar evolution#Stellar remnants that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared the neighbourhood of planetesimals....
s, asteroid

Asteroid

Asteroids, sometimes called minor planets or planetoids, are small Solar System bodies in orbit around the Sun, smaller than planets but larger than meteoroids....
s, etc.) and any surface features on them, and is a member of the International Council for Science

International Council for Science

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Encyclopedia

Star

A star is a massive, luminous ball of Plasma that is held together by its own gravity. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth....
s, planet

Planet

Asteroid

International Council for Science

The International Council for Science , formerly called the International Council of Scientific Unions, was founded in 1931 as an international non-governmental organization devoted to international co-operation in the advancement of science....
(ICSU). The main aim of the IAU 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.

Working groups include the Working Group for Planetary System Nomenclature (WGPSN), which maintains the astronomical naming conventions

Astronomical naming conventions

In ancient times, only the Sun and Moon, a few hundred 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....
and planetary nomenclature

Planetary nomenclature

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....
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

Central Bureau for Astronomical Telegrams

The Central Bureau for Astronomical Telegrams is the official international clearing house for information relating to transient astronomical events....
. The Minor Planet Center

Minor Planet Center

The Minor Planet Center operates at the Smithsonian Astrophysical Observatory , which is part of the Center for Astrophysics along with the Harvard College Observatory ....
(MPC), a clearinghouse for all non-planetary or non-moon bodies in the solar system

Solar System

The Solar System consists of the Sun and those Astronomical object bound to it by gravity: the eight planets and five dwarf planets, their 173 known Natural satellite, and billions of Small Solar System body....
, also operates under the IAU.

History

The IAU was founded in 1919, as a merger of various international projects including the Carte du Ciel
Carte du Ciel

The Carte du Ciel and the Astrographic Catalogue were two distinct but connected components of a massive international astronomical project, initiated in the late 19th century, to catalogue and map the positions of millions of stars as faint as 11th or 12th stellar magnitude....
, the Solar Union and the International Time Bureau

International Time Bureau

The Bureau International de l'Heure or the International Time Bureau, seated at the Paris Observatory, was the international bureau responsible for combining different measurements of Universal Time....
(Bureau International de l'Heure). The first appointed President was Benjamin Baillaud

Benjamin Baillaud

?douard Benjamin Baillaud was a French astronomer....
. Pieter Johannes van Rhijn

Pieter Johannes van Rhijn

Pieter Johannes van Rhijn was a Netherlands astronomer. Born in Gouda, he studied at Groningen . He served as director at the Sterrenkundig Laboratorium in Groningen and later served for many years as president of the International Astronomical Union ....
served as president from 1932 to 1958. In the IAU Information Bulletin No. 100, 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

Nicolaus Copernicus

Nicolaus Copernicus was the first astronomer to formulate a scientifically-based heliocentrism cosmology that displaced the Earth from the center of the universe....
' 500th birthday in February 1973, shortly after the regular GA in Australia.

Composition

The IAU has 9,664 individual members, all of whom are professional astronomers and most of whom hold PhD

PHD

PHD may refer to:* Parisada Hindu Dharma, an Indonesian reform organization* PHD, a track on The Crystal Method album Tweekend* PHD finger, a protein sequence...
s. There are also 65 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

Supermajority

A supermajority or a qualified majority is a requirement for a proposal to gain a specified level or type of support which exceeds a majority in order to have effect....
. 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

World War II

World War II, or the Second World War , was a global military conflict which involved a Participants in World War II, including all of the great powers, organised into two opposing military alliances: the Allies of World War II and the Axis powers....
.

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

Warsaw

Warsaw is the Capital and World's largest cities of Poland. It is located on the Vistula River roughly from both the Baltic Sea coast and the Carpathian Mountains....
, Poland

Poland

Poland , officially the Republic of Poland , is a country in Central Europe. Poland is bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian Enclave and exclave, to the north....
, to commemorate the 500th anniversary of the birth of Nicolaus Copernicus

Nicolaus Copernicus

Nicolaus Copernicus was the first astronomer to formulate a scientifically-based heliocentrism cosmology that displaced the Earth from the center of the universe....
, shortly after the regular 1973 GA was held in Australia.

Meeting	Year	Venue
Ist IAU General Assembly (1st)	1922	Rome Rome Rome is the capital city of Italy and Lazio, and is Italy's largest and most populous city, with 2,724,347 residents in an urban area of some .... , Italy Italy Italy , officially the Italian Republic , is a country located on the Italian Peninsula in Southern Europe and on the two largest islands in the Mediterranean Sea, Sicily and Sardinia....
IInd IAU General Assembly (2nd)	1925	Cambridge Cambridge The city status in the United Kingdom of Cambridge is a College town and the administrative centre of the county of Cambridgeshire, England. It lies about 50 miles north of London.... , England England native_name =\|conventional_long_name = England\|common_name = England\|image_flag = Flag of England.svg\|image_coat = England COA.svg\|symbol_type = Royal Coat of Arms... , United Kingdom United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom , the UK or Britain,is a sovereign state located off the northwestern coast of continental Europe....
IIIrd IAU General Assembly (3rd)	1928	Leiden Leiden Media:Nl-Leiden.ogg is a city and municipality in the province of South Holland in the Netherlands and has 118,000 inhabitants. It forms a single urban area with Oegstgeest, Leiderdorp, Voorschoten, Valkenburg, Rijnsburg and Katwijk, with 254,000 inhabitants.... , Netherlands Netherlands The Netherlands is a country that is part of the Kingdom of the Netherlands. It is a parliamentary democratic constitutional monarchy. The Netherlands is located in North-West Europe, and bordered by the North Sea to the north and west, Belgium to the south, and Germany to the east....
IVth IAU General Assembly (4th)	1932	Cambridge, Massachusetts Cambridge, Massachusetts Cambridge is a city in the Greater Boston area of Massachusetts, United States. It was named in honor of the University of Cambridge in England.... , United States United States The United States of America is a Federal government constitutional republic comprising U.S. state and a federal district. The country is situated mostly in central North America, where its Contiguous United States and Washington, D.C., the Capital districts and territories, lie between the Pacific Ocean and Atlantic Oceans, Borders of the U...
Vth IAU General Assembly (5th)	1935	Paris Paris Paris is the Capital of France and the country's largest city. It is situated on the river Seine, in northern France, at the heart of the ?le-de-France Regions of France .... , France France France , officially the French Republic , is a country whose Metropolitan France is located in Western Europe and that also comprises various Overseas departments and territories of France....
VIth IAU General Assembly (6th)	1938	Stockholm Stockholm is the capital and largest city of Sweden. It is the site of the national Swedish Government of Sweden, the Parliament of Sweden, and the official residence of the Swedish Monarchy of Sweden.... , Sweden Sweden Sweden , officially the Kingdom of Sweden , is a Nordic countries on the Scandinavian Peninsula in Northern Europe. Sweden has land borders with Norway to the west and Finland to the northeast, and it is connected to Denmark by the ?resund Bridge in the south....
VIIth IAU General Assembly (7th)	1948	Zürich Zürich Z?rich is the largest city in Switzerland and the capital of the canton of Z?rich. The city is Switzerland's main commercial and cultural centre and sometimes called the Cultural Capital of Switzerland, the political capital of Switzerland being Berne.... , Switzerland Switzerland Switzerland is a landlocked Swiss Alps country of roughly 7.7 million people in Western Europe with an area of 41,285 km?. Switzerland is a federal republic consisting of 26 states called Cantons of Switzerland....
VIIIth IAU General Assembly (8th)	1952	Rome Rome Rome is the capital city of Italy and Lazio, and is Italy's largest and most populous city, with 2,724,347 residents in an urban area of some .... , Italy Italy Italy , officially the Italian Republic , is a country located on the Italian Peninsula in Southern Europe and on the two largest islands in the Mediterranean Sea, Sicily and Sardinia....
IXth IAU General Assembly (9th)	1955	Dublin Dublin Dublin is both the largest city and capital of Republic of Ireland. It is located near the midpoint of Ireland's east coast, at the mouth of the River Liffey and at the centre of the Dublin Region.... , Ireland Republic of Ireland Ireland is an Island country in north-western Europe. The modern Sovereignty state occupies about five-sixths of the island of Ireland, which was partitioned by the British on 3 May 1921....
Xth IAU General Assembly (10th)	1958	Moscow Moscow Moscow is the capital and the largest types of inhabited localities in Russia of the Russian Federation. It is also the largest European cities and metropolitan areas, with the Moscow metropolitan area ranking among the largest urban areas in the world.... , Soviet Union Soviet Union The Union of Soviet Socialist Republics was a Constitution of the Soviet Union socialist state that existed in Eurasia from 1922 to 1991.The name is a translation of the , romanization of Russian Soyuz Sovetskikh Sotsialisticheskikh Respublik, abbreviated ????, SSSR....
XIth IAU General Assembly (11th)	1961	Berkeley, California Berkeley, California Berkeley is a city on the east shore of San Francisco Bay in Northern California, in the United States. Its neighbors to the south are the cities of Oakland, California and Emeryville, California.... , United States United States The United States of America is a Federal government constitutional republic comprising U.S. state and a federal district. The country is situated mostly in central North America, where its Contiguous United States and Washington, D.C., the Capital districts and territories, lie between the Pacific Ocean and Atlantic Oceans, Borders of the U...
XIIth IAU General Assembly (12th)	1964	Hamburg Hamburg Hamburg is the second-largest city in Germany , and is the Largest cities of the European Union by population within city limits. The city is home to approximately 1.8 million people, while the Hamburg metropolitan area has more than 4.3 million inhabitants.... , West Germany West Germany West Germany was the common English name for the Germany , from its formation in May 1949 to German reunification in October 1990, when East Germany was dissolved and its States of Germany became part of the Federal Republic, ending the more than 40-year division of Germany....
XIIIth IAU General Assembly (13th)	1967	Prague Prague Prague is the Capital and World's largest cities of the Czech Republic. Its official name is Hlavn? mesto Praha, meaning Prague, the Capital City.... , Czechoslovakia Czechoslovakia Czechoslovakia was a sovereign state in Central Europe that existed from October 1918 until 1992 . On January 1, 1993, Czechoslovakia dissolution of Czechoslovakia into the Czech Republic and Slovakia....
XIVth IAU General Assembly (14th)	1970	Brighton Brighton Brighton is a city on the south coast of England and, with its neighbours Hove and Portslade, forms the Brighton and Hove.The ancient settlement of Brighthelmston dates from before the Domesday Book , but it emerged as a health resort during the 18th Century and became a destination for day-trippers after the arrival of the railway in... , England England native_name =\|conventional_long_name = England\|common_name = England\|image_flag = Flag of England.svg\|image_coat = England COA.svg\|symbol_type = Royal Coat of Arms... , United Kingdom United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom , the UK or Britain,is a sovereign state located off the northwestern coast of continental Europe....
XVth IAU General Assembly (15th)	1973	Sydney Sydney Sydney is the List of cities in Australia by population in Australia, with a metropolitan area population of approximately 4.34 million . It is the List of Australian capital cities of New South Wales, and was the site of the first British Empire colony in Australia.... , Australia Australia Australia, officially the Commonwealth of Australia, is a country in the southern hemisphere comprising the Australia of the world's smallest continent, the major island of Tasmania, and numerous list of islands of Australia in the Indian Ocean and Pacific Oceans....
XVIth IAU General Assembly (16th)	1976	Grenoble Grenoble Grenoble is a city in southeastern France situated at the foot of the Alps where the Drac River joins the Is?re River.Located in the Rh?ne-Alpes regions of France, Grenoble is the capital of the Departments of France of Is?re.... , France France France , officially the French Republic , is a country whose Metropolitan France is located in Western Europe and that also comprises various Overseas departments and territories of France....
XVIIth IAU General Assembly (17th)	1979	Montreal Montreal Montreal, or Montr?al, is the largest city in the Provinces and territories of Canada of Quebec and the List of largest cities and second largest cities by country List of the 100 largest municipalities in Canada by population.... , Quebec Quebec Quebec , in French language, *Qu?bec* , is a Provinces and territories of Canada in the Central Canada and Eastern Canada regions of Canada.... , Canada Canada Canada is a country occupying most of northern North America, extending from the Atlantic Ocean in the east to the Pacific Ocean in the west and northward into the Arctic Ocean....
XVIIIth IAU General Assembly (18th)	1982	Patras Patras Patras is Greece's third largest urban centre and the capital of the prefecture of Achaea, located in northern Peloponnese, 215 kilometers west of Athens.... , Greece Greece Greece , officially the Hellenic Republic , is a country in southeastern Europe, situated on the southern end of the Balkans. It has borders with Albania, Bulgaria and the former Yugoslav Republic of Macedonia to the north, and Turkey to the east....
XIXth IAU General Assembly (19th)	1985	New Delhi New Delhi New Delhi is the capital city of India. With a total area of 42.7 km2, New Delhi is situated within the metropolis of Delhi and serves as the seat of the Government of India and the Government of the National Capital Territory of Delhi .... , India India India, officially the Republic of India , is a country in South Asia. It is the List of countries and outlying territories by total area country by geographical area, the List of countries by population country, and the most populous liberal democracy in the world....
XXth IAU General Assembly (20th)	1988	Baltimore, Maryland Maryland Maryland is a U.S. state located in the Mid Atlantic States of the United States, bordering Virginia, West Virginia and the Washington, D.C. to the south and west, Pennsylvania to the north, and Delaware to the east.... , United States United States The United States of America is a Federal government constitutional republic comprising U.S. state and a federal district. The country is situated mostly in central North America, where its Contiguous United States and Washington, D.C., the Capital districts and territories, lie between the Pacific Ocean and Atlantic Oceans, Borders of the U...
XXIst IAU General Assembly (21st)	1991	Buenos Aires Buenos Aires Buenos Aires is the Capital and largest city of Argentina. It is located on the southern shore of the R?o de la Plata, on the southeastern coast of the South American continent.... , Argentina Argentina Argentina, officially the Argentine Republic , is a country in South America, constituted as a federation of 23 provinces and an autonomous city....
XXIInd IAU General Assembly (22nd)	1994	The Hague The Hague The Hague is the third largest city in the Netherlands after Amsterdam and Rotterdam, with a population of 475,904 and an area of approximately 100 km?.... , Netherlands Netherlands The Netherlands is a country that is part of the Kingdom of the Netherlands. It is a parliamentary democratic constitutional monarchy. The Netherlands is located in North-West Europe, and bordered by the North Sea to the north and west, Belgium to the south, and Germany to the east....
XXIIIrd IAU General Assembly (23rd)	1997	Kyoto Kyoto Sorry, no overview for this topic , Japan Japan Japan is an island country in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, People's Republic of China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south....
XXIVth IAU General Assembly (24th)	2000	Manchester Manchester Manchester is a city and metropolitan borough of Greater Manchester, England. Manchester was granted City status in the United Kingdom in 1853.... , England England native_name =\|conventional_long_name = England\|common_name = England\|image_flag = Flag of England.svg\|image_coat = England COA.svg\|symbol_type = Royal Coat of Arms... , United Kingdom United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom , the UK or Britain,is a sovereign state located off the northwestern coast of continental Europe....
XXVth IAU General Assembly (25th)	2003	Sydney Sydney Sydney is the List of cities in Australia by population in Australia, with a metropolitan area population of approximately 4.34 million . It is the List of Australian capital cities of New South Wales, and was the site of the first British Empire colony in Australia.... , Australia Australia Australia, officially the Commonwealth of Australia, is a country in the southern hemisphere comprising the Australia of the world's smallest continent, the major island of Tasmania, and numerous list of islands of Australia in the Indian Ocean and Pacific Oceans....
XXVIth IAU General Assembly (26th)	2006	Prague Prague Prague is the Capital and World's largest cities of the Czech Republic. Its official name is Hlavn? mesto Praha, meaning Prague, the Capital City.... , Czech Republic Czech Republic The Czech Republic , is a landlocked country in Central Europe. The country borders Poland to the northeast, Germany to the west, Austria to the south and Slovakia to the east....
XXVIIth IAU General Assembly (27th)	2009	Rio de Janeiro Rio de Janeiro Rio de Janeiro , is the second largest city of Brazil and South America, behind S?o Paulo, and the third largest metropolitan area in South America, behind S?o Paulo and Buenos Aires.... , Brazil Brazil Brazil , officially the Federative Republic of Brazil , is a country in South America. It is the List of countries and outlying territories by total area country by geographical area, occupying nearly half of South America, the List of countries by population country, and the fourth most populous democracy in the world....
XXVIIIth IAU General Assembly (28th)	2012	Beijing Beijing is a metropolis in northern China and the Capital of the People's Republic of China. It is one of the four municipality of China, which are equivalent to province in China's Political divisions of China.... , China People's Republic of China The People's Republic of China , commonly known as China, is the largest country in East Asia and the List of countries by population in the world with over 1.3 billion people, approximately a fifth of the world's population....

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

Prague

Prague is the Capital and World's largest cities of the Czech Republic. Its official name is Hlavn? mesto Praha, meaning Prague, the Capital City....
, Czech Republic

Czech Republic

The Czech Republic , is a landlocked country in Central Europe. The country borders Poland to the northeast, Germany to the west, Austria to the south and Slovakia to the east....
. 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

Solar System

Pluto

Pluto , Minor planet names Pluto, is the second-largest known dwarf planet in the Solar System and the tenth-largest body observed directly orbiting the Sun....
's present moon Charon

Charon (moon)

'Charon' , discovered in 1978, is the largest moon of the dwarf planet Pluto. Following the 2005 discovery of two other natural satellites of Pluto , Charon may also referred to as 'Pluto I'....
, Eris

Eris (dwarf planet)

'Eris' , Minor planet names '136199 Eris', is the largest known dwarf planet in the Solar System and the ninth-largest body known to orbit the Sun directly....
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

Eris (dwarf planet)

'Eris' , Minor planet names '136199 Eris', is the largest known dwarf planet in the Solar System and the ninth-largest body known to orbit the Sun directly....
and Pluto as dwarf planet

Dwarf planet

A dwarf planet, as defined by the International Astronomical Union , is a celestial body orbiting the Sun that is massive enough to be rounded by its own gravity but has not Clearing the neighbourhood of planetesimals and is not a natural satellite....
s, and reduced the number of planets in the solar system to 8. The voting procedure followed IAU's Statutes and Working Rules. The General Assembly lasted 12 days and had 2412 participants, 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

Eris (dwarf planet)

'Eris' , Minor planet names '136199 Eris', is the largest known dwarf planet in the Solar System and the ninth-largest body known to orbit the Sun directly....
, Mike Brown

Michael E. Brown

Michael E. Brown has been a professor of planetary astronomy at the California Institute of Technology since 2003. He was previously an associate professor at Caltech from 2002-2003 and an assistant professor at Caltech from 1997?2002....
.

International Astronomical Union

History

Composition

General Assemblies

The XXVIth General Assembly and the definition of a planet

See also

External links