Armenianastrophysicist. His major work was on the origin and evolution of stars, for which he was the first to take proper account of their physical properties. He discovered and named stellar associations, and did important early work on radio galaxies and active galactic nuclei. He also studied mass ejection from novae and planetary nebulae. Ambartsumian was instrumental in the founding of Byurakan Astrophysical Observatory.
Subjects: Astronomy and Astrophysics.