Viktor Ambartsumian was one of the greatest astrophysicists of the 20th century and a founding father of theoretical astrophysics. He established the Byurakan Astrophysical Observatory  which rapidly became one of the most important centers of global astronomy. Ambartsumian's discoveries—particularly regarding stellar associations and the activity of galactic nuclei—revolutionized our understanding of cosmic evolution. He led the Armenian Academy of Sciences for many years an