Over the last few years, intensified research and improved observational techniques have led to the discovery of stars which are orbited by companions of very low mass. The data so far available indicate that at least the majority of these have masses comparable to that of Jupiter, the largest planet in our own solar system. None of the companions discovered so far has, however, yet been observed directly. It is therefore conceivable that a few candidates might yet turn out to be stars too small to ignite hydrogen burning in their interiors, so-called brown dwarfs. Efforts to discover more planetary companions to other stars in the Milky Way galaxy are being vigorously pursued and will no doubt feature prominently in astronomical research over the next several decades.
The IAU, through its Division III: Planetary Systems Sciences, provides a forum for international discussion and coordination of research in this exciting new branch of astronomy. The next major opportunity for an in-depth review of the field will be IAU Symposium No. 202, Planetary Systems in the Universe, at the 24th IAU General Assembly. On going work under the auspices of the IAU will focus on the reliability and complementarity of the several techniques used to detect and characterise extra-solar planets. As the number of confirmed cases increases, astronomers will begin to better understand how planetary systems, including our own solar system, form and evolve.
In order to facilitate international research in the field, and as part of these discussions, the IAU is also developing a system for clear and unambiguous scientific designation of these bodies at all stages during their study, from tentative identification to fully-characterized objects. Such a system must take into account that discoveries are often tentative, later to be confirmed or rejected, possibly by several different methods, and that several planets belonging to the same star may eventually be discovered, again possibly by different means. Thus, considerable care and experience are required in its design.
In response to frequent questions about plans to assign actual names to extra-solar planets, the IAU sees no need and has no plan to assign names to these objects at the present stage of our knowledge. Indeed, if planets are found to occur very frequently in the Universe, a system of individual names for planets might well rapidly be found equally impracticable as it is for stars, as planet discoveries progress.
The Executive Committee consists of the President of the Union, the President-Elect, six Vice-Presidents, the General Secretary, and the Assistant General Secretary elected by the General Assembly on the proposal of the Special Nominating Committee (SNC). The Executive Committee is seconded by two Advisers, namely the past President and the past General Secretary.
The Officers of the Union are the President, the President-Elect, the General Secretary, and the Assistant General Secretary. They decide short-term policy issues within the general policies of the Union as decided by the General Assembly and interpreted by the Executive Committee.
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Your are able to modify your username and password, when logged, in your Identity Form (in “modify” mode). The International Astronomical Union (IAU) was founded in 1919. Its mission is to promote and safeguard the science of astronomy in all its aspects through international cooperation. Its individual members are professional astronomers all over the World, at the Ph.D. level or beyond and active in professional research and education in astronomy. However, the IAU maintains friendly relations also with organizations that include amateur astronomers in their membership. National Members are generally those with a significant level of professional astronomy. The IAU is composed of 8,858 Individual Members in 85 different countries worldwide out of which 62 are National Members (according to statistics of August 2006).
The IAU also serves as the internationally recognized authority for assigning designations to celestial bodies and any surface features on them. News 6 Resolutions adopted at GA-XXVI Updated Statutes, Bye Laws & Working Rules now on-line News from IAU XXVIth General Assembly Newsletter n° 5 now available The Peter Gruber Fellowships 2006
Dates and Deadlines November 01, 2006 Contributions for Highlights of Astronomy Volume 14 due at IAU Secretariat November 01, 2006 Contributions for Transactions XXVIB due at IAU due at IAU Secretariat
December 01, 2006 2008 IAU meetings: Due date for each IAU scientific meeting proposers to submit to the IAU Proposal Website the final proposal and a file containing scientific rationale, draft program, tentative speakers list, and a report of communication with DPs, CPs and/or WGPs
From time to time, we have all seen stories in the Press about Near Earth Objects that are about to hit the Earth on some date in the not-too-distant future. Sometimes the IAU is mentioned in the story. The aim here is to briefly describe what the normal practice is when a NEO is discovered and what part the IAU might be seen to play in this process. In fact, the basic procedure is the same whether the discovery is of a comet, a Kuiper belt object, a Main belt asteroid or any other minor body in the Solar System. When an observer discovers a body that is moving relative to the background, the information is always sent to the IAU Minor Planet Center (MPC) located at the Smithsonian Astrophysical Observatory in Cambridge, MA, USA.
This information should always give the position of the body (Right Ascension and Declination) and the time of the observation (using UT) for each observation made. Most observers will try to obtain at least three such sets of observations during the night. Though observers may try to derive an orbit for the object from their observations, this orbit is not usually sent to the MPC, the orbit that is made public comes from calculations made at the MPC. With data from a single night, only the crudest of orbits can be determined. Mostly, the initial discoverers have further nights scheduled at the telescope, or know of colleagues who have telescope time, so that additional observations of the body come about as a matter of course. This usually is sufficient information to allow the MPC to generate a reasonable orbit and the discovery is announced, in general as part of the MPC Electronic Circular system. In order to obtain a more reliable orbit, further observations, well separated in both space and time from the discovery observations are required. For most bodies in the Solar System, these observations are obtained as part of other programmes, usually on a time scale of months, and this is perfectly adequate to allow the body to be permanently recorded.
The initial discoverers may, for a number of reasons, be unable to obtain additional observations themselves. To aid the process of obtaining additional observations, the MPC produces a list that is generally available of objects that need further observations and are currently visible so that observers with telescope time can make a special effort to observe these objects, thus ensuring that the elements of the orbit are secure. The Near Earth Objects are peculiar in that they are far easier to detect when close to the Earth and thus appear to move very fast against the background and, unless additional observations are obtained very quickly, the body may be lost. In this event, the MPC may become pro-active and solicit observations from known observers, or release a preliminary orbit, with large error bars, so that other observers will know roughly where on the sky this particular object is so that they can conduct a search for it. Sometimes it is found in archival records.
The problem that I alluded to in the first sentence appears when predictions for the future motion of the body, based on the rather poor initial orbit, indicate that collision with the Earth is a very remote possibility sometime in the distant future. The dilemma is obvious.
If the rough orbit is not released, there is little chance of further observations being obtained. If the orbit is released, it is inevitable that somebody will compute into the future and find that there is a small probability of an Earth collision.
The IAU Minor Planet Center is central to the process as it currently operates, and so it is not surprising that the press often state that “the IAU announces that an asteroid may hit the Earth in 20XX”.
In addition to being co-sponsors of the MPC, IAU Division III also has a Working Group on Near Earth Objects (Chair D. Morrison). It is not as a WG directly involved in observations (though individual members may of course be observers), its role is to further the science and understanding of Near Earth Objects. It consists of a number of experts in the field and so many of its members, quite naturally, also often are approached by the Press for comment.
The International Astronomical Union (IAU) was founded in 1919. Its mission is to promote and safeguard the science of astronomy in all its aspects through international cooperation. Its individual members are professional astronomers all over the World, at the Ph.D. level or beyond and active in professional research and education in astronomy. However, the IAU maintains friendly relations also with organizations that include amateur astronomers in their membership. National Members are generally those with a significant level of professional astronomy. The IAU is composed of 8,858 Individual Members in 85 different countries worldwide out of which 62 are National Members (according to statistics of August 2006).
The IAU also serves as the internationally recognized authority for assigning designations to celestial bodies and any surface features on them.