John R. Percy, University of Toronto. President of IAU Commission 46. Mercury, march-april 1995, p. 18. About 60 countries now adhere to the IAU through national organizations, such as academies of science. Adhering countries nominate individual members, who usually must have an avanced degree in astronomy and professional experience.
Membership is free.
Each adhering country contributes to the IAU budget according to its state of development and number of individuals members. Most of the funds encourage and support astronomy in the less-developed countries. The IAU holds a General Assembly every three years, as well as Regional Meetings and specialized conferences. Most of the conferences address research, but a few have dealt with other aspects of astronomy such as education, history, and amateurs. The IAU provides travel grants to young astronomers from countries with limited resoruces.