The IAU was founded in 1919 to promote and safeguard the science of astronomy in all its aspects through international cooperation. Its individual members are professional astronomers from all over the world, at the Ph.D. level and beyond, who are active in professional research and education in astronomy.
The IAU General Assembly is held every three years, the next one will take place in August 2021.
How to join
Professional scientists whose research is directly relevant to some branch of astronomy are eligible for election as Individual Members. The RAS, as the UK 'National Member' of the IAU , is responsible for vetting and forwarding nominations to the IAU. To apply for membership of the IAU please contact the RAS Membership Officer. For more information about the qualification rules and application procedure please see the IAU website.
While it is not a condition that UK members of the IAU are Fellows of the RAS it is encouraged since the President of the Society is called upon to vote on behalf of all UK members. Clearly it is preferable that they can be consulted through the Society's normal channels. An additional consideration is that IAU Members do not pay dues to the Union, fees are covered by the RAS and Royal Society.