Rules and Guidelines for Hosting IAU General Assemblies
Last updated: May 2026
Every three years the International Astronomical Union (IAU) has its General Assembly (GA) where it offers a rich scientific program to its members and conducts its administrative business. The proceedings of the scientific program of each GA are published, currently by Cambridge University Press. The Focus Meetings are combined into an issue called Astronomy in Focus, the symposia are published each in a separate issue, and the administrative business is documented in an issue called Transactions.
In this document, 'Host' refers collectively to the National Organizing Committee (NOC), Local Organizing Committee (LOC), and supporting national institutions.
Contents
SCHEDULE OF GENERAL ASSEMBLY AND MAIN SCIENTIFIC EVENTS
An IAU General Assembly (GA) is scheduled over eight days of a two-week period, from Tuesday through Friday of the first week, with registration starting on the preceding Monday, and from Monday through Thursday of the second week. The plenary Opening Ceremony is held on the Tuesday afternoon of the first week, and the plenary Closing Ceremony is held on the Thursday afternoon of the second week. The GA is normally in August; the exact dates may be set depending on local arrangements and are to be discussed with the IAU General Secretary (GS).
The scientific program normally comprises six Symposia, each of three days in duration. Three Symposia are scheduled during the first week, and three during the second week. Also held during the eight working days are a number of Focus Meetings, each lasting one to two days, and nine Division Meetings, each with sessions on two days. The selection of Symposia and Focus Meetings is made by the IAU Executive Committee (EC), following recommendations from an ad-hoc evaluation committee composed of the IAU Vice-Presidents and Division Presidents.
Each Symposium, Focus Meeting and Division Meeting is organized by its own international Scientific Organizing Committee (SOC), which liaises with the Host through designated representatives. The SOC is responsible for the scientific content of its meeting, including the review of abstracts and preparation of its scientific program. Additional SOCs may be associated with meetings organized by the IAU Offices and some of the IAU Working Groups.
Three Invited Discourses (ID) by distinguished scientists, selected and invited by the IAU, are normally held as plenary science sessions, open to all participants and accompanying guests.
The above scientific events and associated events are open to all registered participants of the GA.
Many administrative and business meetings are also held during the GA. The EC has its own administrative meetings, and some or all of the EC may meet with the National Representatives, the Finance Committee, the Special Nominating Committee, the Membership Committee, the Resolutions Committee, and the Division Presidents. Other business meetings may be incorporated into scientific sessions allocated for Division Meetings, and meetings of the IAU Offices or Working Groups.
The above-mentioned activities require a program of eight working days with roughly ten parallel science sessions. The IAU is responsible for the overall scheduling of the meetings and room allocation shall be coordinated jointly by the IAU and the host.
NON-DISCRIMINATION AND INCLUSIVITY
An IAU GA follows the IAU Code of Conduct and the regulations of the International Science Council, and concurs with the actions undertaken by their Standing Committee on Freedom in the Conduct of Science on non-discrimination and universality of science. The IAU strives to achieve a diverse and inclusive meeting, as emphasized in its Springboard to Action. The locale of the GA should be welcoming to all members of our community.
VENUE REQUIREMENTS
Recent GAs have been attended by 2000-3000 participants. Although the GA program should be sufficiently broad to attract such numbers of participants, not all will stay for the entire two weeks, depending on an individual’s interest in the various individual sessions. Estimates based on past GAs indicate that about 1/3 of the participants attend one of the two weeks, and 1/3 attend both weeks.
Minimum room requirements are:
- One major hall seating at least 3000 persons, required for the GA plenary sessions (Opening and Closing Ceremonies and two Business Sessions), plus daytime plenary sessions and evening IDs
- Three lecture rooms seating 500-600 persons, required during all eight working days of the GA for the Symposia.
- Four lecture rooms seating 250-400 persons, required during all eight working days, for the larger other scientific meetings.
- At least three smaller lecture rooms seating 100-120 persons, required during all eight working days, for the smaller other scientific meetings.
- One room seating 100 persons for business meetings of the Executive Committee with the National Representatives, the Nominating Committee, the Finance Committee and the Resolutions Committee etc.
- Two rehearsal rooms for presentations using slides and digital projectors. Rehearsals require on-the-spot assistance of specialists concerning all specialized audio-visual equipment needed in the conference rooms.
- Space adequate for Poster Sessions, either physical or electronic (as a reference 2,500 square meters).
- Two large lounge spaces for general use.
- Quiet space for participants with disabilities or special needs.
- One additional large room with Wi-Fi and projection and sound equipment—adequate capacity for Young Astronomers Lunch and Women in Astronomy Lunch (typically 400 people).
- IAU exhibition space (at least 100 square meters): IAU and its Offices should be near the main entrance, very central, as this will be the first image in the GA.
The IAU staff and functions require the following office space with Wi-Fi:
- Secretariat: one room with printer/copier.
- President: one room.
- President-Elect: one room.
- General Secretary: one room seating 20 persons for business meetings.
- Assistant General Secretary: one room with two desks.
- IAU Grant distribution close to the secretariat: one room.
- One room for use of IAU Committees such as the Resolutions Committee and Finance Committee.
- Four rooms, one each for the IAU Offices.
- Media provision with projection and sound equipment: one Press Room seating 20 persons, one Press Room seating 30 persons and one Press Interview Room seating 10 persons.
- GA Newspaper: one room seating at least three persons and their equipment.
Wireless modern broadband Internet access should be available throughout the GA venue.
Preference should be given to venues offering the possibility to hold the entire General Assembly under one roof.
HYBRID OPTIONS
The IAU was founded to bring astronomers together and values face-to-face General Assemblies to allow the greatest opportunities for networking and exchanging ideas. Travel grants and childcare are available to assist attendance (the host is expected to provide childcare facilities). However, many people are unable to travel, for a variety of reasons. Thus, the GA should include a virtual component. The scope of this component may range from limited access to plenary sessions and electronic posters to broader participation in parallel sessions, depending on available resources. The level of interaction (e.g., inclusion of online participants in questions and answers) and access to recordings should be defined by the Host in consultation with the IAU, taking into account cost, technical feasibility, and inclusivity, and should be reflected in the proposed GA budget. Proposals offering a full hybrid option will receive special consideration.
SERVICES TO BE OFFERED BY THE HOST
The Host shall, at least 1.5 years in advance, create and maintain a GA web site, providing all necessary information for the GA, electronic registration, electronic hotel booking, and electronic ordering of GA proceedings.
The Host shall produce the electronically-accessible Program Book for the General Assembly and the Abstract Book for the science meetings. Content for these books shall be provided by the IAU no later than four weeks before the General Assembly. Last-minute updates are likely.
The Host will prepare different categories of badges, in consultation with the IAU EC.
Upon arrival, all participants will receive from the Host a satchel (with attached name badge) containing at least:
- a Name Badge.
- Basic useful information on the program and room locations, and information on electronic access to the GA Program and Abstract books.
- Local maps and other relevant information.
The Host offers a Welcoming Reception for all participants on the evening of the First Session of the GA, at no cost to the participants.
The Host is responsible for the preparation, printing and distribution of the daily GA Newspaper in electronic or print form. A copy of all the daily printed newspapers or daily digitized PDF versions (in at least 150 DPI) must be delivered to the IAU Secretariat within two weeks of the end date of the GA.
Coffee and tea breaks are to be included in the Registration fee.
Social events, e.g., closing dinner, concerts, post-meeting tours or tours on the free Saturday and Sunday are optional; an additional charge for them is acceptable if necessary.
The Host is expected to offer all normal services associated with the running of a large international scientific meeting, like a Registration Desk, an Information Desk, a Travel Desk, a Hotel Booking desk, Bank Services, First Aid and Childcare options.
ASSOCIATED EVENTS
The IAU is in association with a number of Foundations who celebrate their major prizes during the GA, often with special lectures. For example, the Gruber Foundation (TGF) offers its Cosmology Prize annually. To celebrate further, the TGF normally organizes a reception and private dinner, in consultation with the Host and the IAU.
It is customary that the Host takes advantage of the presence at the GA of numerous highly qualified specialists in astronomy and astrophysics, by organizing events with their collaboration for the general public, in particular teachers.
ACCOMMODATION AND LOCAL TRANSPORTATION FOR PARTICIPANTS
In keeping with the strong desire of the IAU to allow as many astronomers as possible to attend the GA regardless of the financial conditions at their home institutes, availability of affordable accommodation is an important consideration in the selection of a venue for an IAU GA. Inexpensive accommodation can include university student dormitory rooms, assuming that the GA is held outside university terms.
While university dormitories may offer single rooms only, a good supply of cheap hotel double rooms (at least 500-1000) should be available, with the option of advance block booking. Again, most rooms should be in the low-to-middle price range; very few astronomers require luxury rooms.
Similarly, low-cost restaurants should be available in large quantity nearby, including quick and cheap facilities for informal lunch meetings.
Easy access and transportation between hotels, dormitories, and the venue of an IAU GA is highly desirable.
NATIONAL SUPPORT
The governmental bodies of a Host, as well as its astronomical institutions, must commit themselves to provide adequate financial contributions and guarantees to the organizing and running of an IAU General Assembly. In addition, an IAU GA will require extensive manpower support from the national astronomical communities, staff and students. An invitation to host an IAU GA must demonstrate such national interest and quantify the support to be offered.
The GA Host shall play an active role in promoting the GA, nationally and well as internationally, via a dedicated GA web site, posters, and live presentations at national and international astronomical meetings in the year leading up to the GA.
It is a sign of national support that the host country's National Member has a good record of paying its annual membership dues to the IAU on time.
GA EXPENDITURE FOR THE IAU AND THE HOST
Representatives of the IAU Executive Committee will annually visit the Host during the three years before the GA to discuss GA matters.
In the course of the preparation of the GA, the IAU will make available for the Host its web site, and the email distribution list of its roughly 13,000 active members, to announce details about the GA, as well as a list of a large number of astronomical libraries and institutes.
The IAU will sponsor the scientific program of the GA by offering a number of IAU Travel Grants to participants, to be selected and allocated in accordance with its rules for distribution of these, upon recommendation by the SOCs of the main scientific events. This financial contribution is not to be included in the budget of the Host.
The Registration Fee for the GA, a flat rate for all participants, needs the approval of the IAU EC as part of the acceptance of the invitation. At the date of most recent update of this document, the accepted ceiling is 660 EUR. Special categories of reduced fees may also be created (students, senior or retired participants, etc.). Virtual attendees should have a reduced fee.
The Host is responsible for all local financial arrangements of the GA, including the cost of the meeting venue and any assistance of a Professional Conference Organiser (PCO) or others in organising and running the GA. Apart from providing grants to some participants and supporting attendance of some other individuals, such as EC members, and apart from the IAU support in announcing the meeting (as mentioned above), the IAU does not provide a financial contribution to the operation of the GA.
The Host will need to raise substantial additional funding from various sponsoring sources, to keep the registration fee below the accepted ceiling. This should be in consultation with the IAU.
The Host normally organizes an Exhibition, with exhibition space to be rented out to telescope-building companies, aerospace companies, computer companies, scientific publishers, research agencies, major observatories, etc. This Exhibition should provide income for the Host, helping to cover its expenses. At this Exhibition, the Host is expected to offer, free of charge, adequate exhibition space to the IAU and its Offices, and to the Host of the subsequent GA.
An invitation to host an IAU GA must include in its bid book a comprehensive draft budget, demonstrating sound financial conduct.
MEMORANDUM OF UNDERSTANDING (MOU) BETWEEN THE HOST AND IAU
Based on the proposals received for hosting an IAU General Assembly, the IAU Executive Committee will select a first and second candidate during the GA that is held two GA's before the proposed GA.
Immediately after the selection, the IAU will prepare a MoU specifying the responsibilities for the various elements discussed above. In the event that the candidate-Host should be unable to fulfill the specified conditions and to sign the MoU with the IAU within six months, negotiations will be taken up with the second candidate-Host.
DEADLINES FOR GA-HOSTING LETTERS OF INTENT, ADDITIONAL QUESTIONS AND FULL PROPOSALS
LETTERS OF INTENT
Once a Call for Candidature to host a General Assembly is issued, a Letter of Intent proposing to host the IAU General Assembly (GA) should reach the IAU General Secretary (GS) before 1 November of the year that is seven years before the year of the GA.
ADDITIONAL QUESTIONS
All proposers should also send the following details to the GS by 1 December of the year that is seven years before the year of the GA. There will be a down-select to four proposers on or about 15 December based on the information provided. Although this is a preliminary phase of the proposal preparation, and several details are still to be defined, some basic facts should be already available.
General
- What makes your proposal unique?
- Please state why the GA should be organized in your Country, in particular what the IAU will gain in coming to your Country and what your community (astronomers and society) will gain in hosting the GA.
- What are the unique attractions of your location?
- Which side activities (outreach, arts, performances, tours) do you foresee?
- Did your Country host an IAU GA in the past? If yes, when? (obviously this information is available, but your answer will speed up the process)
Logistics
- Location: What is the selected location for the GA? Give a short description demonstrating that it can hold 2500-3500 participants and accommodate the scientific meetings and logistics office space specified above.
- Describe the approach to hybrid options.
- Accommodation: Describe the hotels available in the proximity of the GA location (categories, price range, distance from the GA and from the City Centre). Describe also the availability of low-budget accommodations, especially important for Junior Members and students.
- Transportation: Describe proximity to airport, airport shuttle, trains, general transportation.
- Visa: List the Countries for which a visa is required to enter your Country. Highlight any case for which a visa may not be released or would need special attention.
- Security: Do you envisage any security issue that would require specific recommendations to the participants (areas to be avoided, recommended attire and behaviour, etc.)?
Budget
- Budget and support: How do you intend to enhance the organization of the GA?
- Which are the expected supporting organizations? (no acronyms)
- Please give a rough breakdown of the foreseen budget, specifying expected income and cost.
- Support to junior participants: Describe the measures that you envisage providing to facilitate the participation by junior members and students.
FULL PROPOSALS
For those invited to submit a full proposal (which follows the Additional Questions with all details), the deadline for submitting Bid Books is 1 April of the year six years before the proposed GA, to be sent to the GS.