The scientific collaboration and friendship between the Armenian and Georgian astronomers were established since 1930s due to Viktor Ambartsumian’s (1908-1996) and Evgeni Kharadze’s (1907-2001) efforts. Ambartsumian, working at that time at the Leningrad State University (LSU), several times visited the Abastumani Astrophysical Observatory (AbAO) founded in 1932 as a scientific adviser. The famous Georgian astronomers Mikhail Vashakidze and Shalva Gordeladze were Ambartsumian’s PhD students at LSU and a number of important results were published resulting in PhD theses in 1936 and 1937, respectively. In 1946, the Byurakan Astrophysical Observatory (BAO) was founded and the collaboration was continued at a new level. Many Armenian and Georgian astronomers collaborated and published joint papers, important to mention among them Lyudwik Mirzoyan and Guram Salukvadze working on stellar associations, flare and T Tau stars, etc.

Scientific seminars between BAO and AbAO astronomers with mutual visits were rather often resulting in the idea to meet more regularly. In 1974, due to Ambartsumian’s and Kharadze’s initiative, Joint Byurakan-Abastumani (Armenian-Georgian) Colloquia regular series was started and continued till the disintegration of the Soviet Union. Again, Lyudwik Mirzoyan and Guram Salukvadze (both as Deputy Directors of BAO and AbAO, respectively) played decisive role in the organization of these meetings. During 1948-1990, 12 Georgian astronomers defended their PhD (10) and Doctoral (2) theses in Yerevan and Byurakan, among them, Rezo Natsvlishvili was Lyudwik Mirzoyan’s PhD student (defended in 1988) and spent a few years at BAO. E. K. Kharadze and later G. N. Salukvadze were members of BAO Special Council for theses defenses. Similarly, E. K. Kharadze and later G. N. Salukvadze were elected as members of the Editorial Board of the journal Astrofizika/Astrophysics. Later on, due to the efforts of present generation scientists, the series was renovated and several meetings were held since 1998. Unfortunately, it is not very regular at the modern times, however, the willingness to collaborate is still active. The last several colloquia (1998, 2003, 2013) were dedicated to Lyudwik Mirzoyan’s anniversaries.

In 2008-2010, due to the initiative by Areg Mickaelian, the Armenian and Georgian astronomers accomplished a joint International Science and Technology Centre (ISTC) project on the development of the Armenian and Georgian virtual observatories (VOs). On the other hand, in 2015 Armenia became one of the International Astronomical Union (IAU) Regional Offices of Astronomy for Development (ROAD), namely for the South West and Central Asia (SWCA), and Georgia was one of the first to support and join this initiative. Many Georgian astronomers and students participated in the international and regional meetings and schools organized in Byurakan in 2015-2022.

The XV Joint Byurakan-Abastumani Colloquium is being organized on 1-5 May 2023 in Byurakan and is dedicated to Lyudwik Mirzoyan’s 100^th anniversary. 27 Armenian and 11 Georgian astronomers are participating.

The Byurakan Astrophysical Observatory (BAO) is at present one of the most active scientific research institutions of the Armenian National Academy of Sciences (NAS RA), an Armenian National Value (recognized in 2013), an IAU Regional Centre (2015), hosts UNESCO “Memory of the World” documentary heritage (2011, Markarian Survey), is included in the IAU Outstanding Astronomical Heritage (OAH, 2021), and its park is recognized as an Arboretum (2017). Many important meetings have been organized by BAO, including 7 IAU meetings (1966, 1986, 1989, 1998, 2001, 2013, 2023), European Annual Astronomical Meeting (JENAM-2007), the first international conference on CETI (1971), UNESCO Regional Conference (2017), Symposia Astronomical Surveys and Big Data (ASBD, 2015, 2020) and many others. In 2006, BAO started the Byurakan International Summer Schools (BISS) regular series and so far, 8 schools have been organized. In 2019, BAO started another series; Regional Astronomical Summer Schools (RASS) and the 3^rd RASS will be held in 2023.

English and russian are working languages of the colloquium.