A planetary-mass object ( PMO ), planemo , or planetary body (sometimes referred to as a world ) is, by geophysical definition of celestial objects , any celestial object massive enough to achieve hydrostatic equilibrium , but not enough to sustain core fusion like a star .
31-409: Offworld or off-world may refer to: in science fiction, the quality of being on another planetary body or in space Offworld Trading Company , real-time strategy video game Offworld , a blog that became part of the website Boing Boing Offworld (album) , the fourth vocal album by electronic rock project Celldweller Topics referred to by
62-542: A larger object such as 2MASS J04414489+2301513 . Binary systems of sub-brown dwarfs are theoretically possible; Oph 162225-240515 was initially thought to be a binary system of a brown dwarf of 14 Jupiter masses and a sub-brown dwarf of 7 Jupiter masses, but further observations revised the estimated masses upwards to greater than 13 Jupiter masses, making them brown dwarfs according to the IAU working definitions. Rogue planets in stellar clusters have similar velocities to
93-408: A subtype of planet. The International Astronomical Union (IAU) accepted the term (rather than the more neutral 'planetoid') but decided to classify dwarf planets as a separate category of object. In close binary star systems, one of the stars can lose mass to a heavier companion. Accretion-powered pulsars may drive mass loss. The shrinking star can then become a planetary-mass object. An example
124-416: A system ( rogue planets ) or formed through cloud-collapse rather than accretion ( sub-brown dwarfs ). While the term technically includes exoplanets and other objects, it is often used for objects with an uncertain nature or objects that do not fit in one specific class. Cases in which the term is often used: The three largest satellites Ganymede , Titan , and Callisto are of similar size or larger than
155-564: 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), is 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
186-427: Is a Jupiter-mass object orbiting the pulsar PSR J1719−1438 . These shrunken white dwarfs may become a helium planet or carbon planet . Stars form via the gravitational collapse of gas clouds, but smaller objects can also form via cloud collapse . Planetary-mass objects formed this way are sometimes called sub-brown dwarfs. Sub-brown dwarfs may be free-floating such as Cha 110913−773444 and OTS 44 , or orbiting
217-677: Is a member of the International Science Council , which is composed of international scholarly and scientific institutions and national academies of sciences . The International Astronomical Union is an international association of professional astronomers , at the PhD level and beyond, active in professional research and education in astronomy . Among other activities, it acts as the recognized authority for assigning designations and names to celestial bodies ( stars , planets , asteroids , etc.) and any surface features on them. The IAU
248-529: Is a member of the International Science Council . 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 . This organisation has many working groups. For example,
279-468: 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,
310-750: 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. In 2004 the IAU contracted with the Cambridge University Press to publish the Proceedings of the International Astronomical Union . In 2007, the Communicating Astronomy with the Public Journal Working Group prepared
341-788: Is an international non-governmental organization (INGO) with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and development through global cooperation. It was founded on 28 July 1919 in Brussels , Belgium and is based in Paris , France . The IAU is composed of individual members, who include both professional astronomers and junior scientists, and national members, such as professional associations, national societies, or academic institutions. Individual members are organised into divisions, committees, and working groups centered on particular subdisciplines, subjects, or initiatives. As of May 2024,
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#1732863065884372-533: Is different from Wikidata All article disambiguation pages All disambiguation pages Planetary body The purpose of this term is to classify together a broader range of celestial objects than ' planet ', since many objects similar in geophysical terms do not conform to conventional expectations for a planet. Planetary-mass objects can be quite diverse in origin and location. They include planets , dwarf planets , planetary-mass satellites and free-floating planets , which may have been ejected from
403-477: Is in direct orbit of a star, and is massive enough for its gravity to compress it into a hydrostatically equilibrious shape (usually a spheroid), but has not cleared the neighborhood of other material around its orbit. Planetary scientist and New Horizons principal investigator Alan Stern , who proposed the term 'dwarf planet', has argued that location should not matter and that only geophysical attributes should be taken into account, and that dwarf planets are thus
434-568: 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. Since 1922, the IAU General Assembly meets every three years, except for 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
465-837: The International Central Bureau of Astronomical Telegrams initially seated in Copenhagen , Denmark. The seven initial member states were Belgium, Canada, France, Great Britain, Greece, Japan, and the United States, soon to be followed by Italy and Mexico. The first executive committee consisted of Benjamin Baillaud (President, France), Alfred Fowler (General Secretary, UK), and four vice presidents: William Campbell (US), Frank Dyson (UK), Georges Lecointe (Belgium), and Annibale Riccò (Italy). Thirty-two Commissions (referred to initially as Standing Committees) were appointed at
496-758: 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. 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
527-461: 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 to be valid. An absolute majority
558-567: 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, Czechoslovakia, Denmark, the Netherlands, Norway, Poland, Romania, South Africa, and Spain) had joined
589-640: The IAU, an Extraordinary IAU General Assembly was held in September 1973 in Warsaw , Poland, to commemorate the 500th anniversary of the birth of Nicolaus Copernicus , soon after the regular 1973 GA had been held in Sydney. Sources. 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
620-817: The IAU, and is a "clearinghouse" for all non-planetary or non-moon bodies in the Solar System. The IAU was founded on 28 July 1919, at the Constitutive Assembly of the International Research Council (now the International Science Council ) held in Brussels , Belgium. 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
651-930: 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), the Council of German Observatories, the Royal Astronomical Society (United Kingdom),
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#1732863065884682-630: The Union had 85 national members and 12,734 individual members, spanning 90 countries and territories. Among the key activities of the IAU is serving as a forum for scientific conferences. It sponsors nine annual symposia and holds a triannual General Assembly that sets policy and includes various scientific meetings. The Union is best known for being the leading authority in assigning official names and designations to astronomical objects , and for setting uniform definitions for astronomical principles. It also coordinates with national and international partners, such as UNESCO , to fulfill its mission. The IAU
713-675: The Union held the NameExoWorlds contests. Starting in 2024, the Union, in partnership with the United Nations , is poised to play a critical role in developing the legislation and framework for lunar industrialization . As of 1 August 2019, the IAU has a total of 13,701 individual members , who are professional astronomers from 102 countries worldwide; 81.7% of individual members are male, while 18.3% are female. Membership also includes 82 national members , professional astronomical communities representing their country's affiliation with
744-528: The Union's history are well documented. 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. Six past IAU Presidents in the period 1976–2003 also contributed their recollections in IAU Information Bulletin No. 104. In 2015 and 2019,
775-615: 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). The first 50 years of
806-652: 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 catalogues 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
837-409: The liquid is methane rather than water). Proponents of the geophysical definition of planets argue that location should not matter and that only geophysical attributes should be taken into account in the definition of a planet. The term satellite planet is sometimes used for planet-sized satellites. A dwarf planet is a planetary-mass object that is neither a true planet nor a natural satellite; it
868-526: The planet Mercury ; these and four more – Io , the Moon , Europa , and Triton – are larger and more massive than the largest and most massive dwarf planets, Pluto and Eris . Another dozen smaller satellites are large enough to have become round at some point in their history through their own gravity, tidal heating from their parent planets, or both. In particular, Titan has a thick atmosphere and stable bodies of liquid on its surface, like Earth (though for Titan
899-413: The same term [REDACTED] This disambiguation page lists articles associated with the title Offworld . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Offworld&oldid=1233868620 " Category : Disambiguation pages Hidden categories: Short description
930-403: The stars and so can be recaptured. They are typically captured into wide orbits between 100 and 10 AU. The capture efficiency decreases with increasing cluster volume, and for a given cluster size it increases with the host/primary mass. It is almost independent of the planetary mass. Single and multiple planets could be captured into arbitrary unaligned orbits, non-coplanar with each other or with
961-430: The stellar host spin, or pre-existing planetary system. Several computer simulations of stellar and planetary system formation have suggested that some objects of planetary mass would be ejected into interstellar space . Such objects are typically called rogue planets . International Astronomical Union The International Astronomical Union ( IAU ; French : Union astronomique internationale , UAI )