The International Astronomical Union (IAU) was formed in 1919 as a founding member of the International Council of Scientific  Unions (ICSU) and is one   of the oldest International Scientific Unions. Its primary aims are to promote astronomy in all its  international  aspects.  The Union has held more than 200 major scientific meetings since its inception, and the most important of these are its General Assemblies, held once every three years. The first of these was in Rome, Italy in 1922, and the nineteenth such General Assembly takes place in New Delhi, India from 19-28 November, 1985, by invitation of the Indian National Science Academy. This is the first time a General Assembly of the Union is being held in India, and is a result of the efforts of the late Dr. M.K. Vainu Bappu who was its first Indian President having held office from 1979-82.

The IAU General Assemblies are usually attended by a significant fraction of its members who number over 5000 professional astronomers from practically every country in the world. Many of the participants  will be young scientists, and many will come from countries  where research  in astronomy  and  astrophysics has not yet been fully developed. Several interesting scientific and administrative sessions will be held by the Union's 41 Commissions during the ten days of the General Assembly covering every branch of astronomy from the study of the Solar System to the Origin of the Universe. The progress in ongoing International Co­-operative projects will be reviewed and new collaborative programmes will be instituted. India  has been a member of the International Astronomical Union from 1946. Over the years it has contributed more and more to this fascinating science, which apart from its great popular appeal, has also made significant contributions to various fields of application such as optics, electronics and computer science.

The  Department  of  Posts  is  happy to mark the occasion of the first International Astronomical Union General Assembly to be held in India by the issue of a commemorative  stamp.

Source : Information Folder issued by Indian Posts & Telegraph Department, Government of India