Marat Arsen Arakelian () () (15 January 1929 – 20 January 1983) was an Armenian astronomer. Arakelian was a specialist in theoretical astrophysics and extragalactic astronomy. He is most noted for his catalog of “Galaxies of high surface brightness” (named Arakelian galaxies, Akn), a list of 621 objects with surface brightness at least 22.0 magnitude from an area of 1 sq. arc second. The Arakelian catalog has become a source in the study of active galactic nuclei. Early life and education Arakelian was born in Goris, Syunik Province in the Armenian Soviet Socialist Republic, a Soviet republic (now the Republic of Armenia). He attended the Yerevan State University (YSU) in the Physical-Mathematical Department and graduated in 1951. He was among the first YSU students specialized in astrophysics. Arakelian was assigned to the Byurakan Astrophysical Observatory (BAO), where he worked first as assistant astronomer, and later as junior research associate. His postgraduate study at Leningrad State University (now Saint Petersburg State University, St. Petersburg) was completed in 1955, and in 1956 he successfully defended his Ph.D. thesis “Spectrophotometric investigation of Algol” under the supervision of Prof. Oleg Aleksandrovich Melnikov at LSU. Career From 1957 to 1959, Arakelian combined his work with a senior teacher position at the Department of Astrophysics at Yerevan State University. Aralekian was a junior researcher and lectured at the Leningrad State University from 1960 to 1966. After being awarded the title of Associate Professor in 1966, Arakelian again joined the staff at Byurakan Astrophysical Observatory, combining his research with a position as lecturer at Yerevan. Together with L.V. Mirzoyan, A.T. Kalloghlian, and H.M. Tovmassian, he was the co-author of the textbook Astronomy for secondary schools (three editions in 1970, 1971, and 1973). In 1967, he became a senior researcher at the Byurakan Astrophysical Observatory. In 1977, Arakelian defended his second doctoral thesis "Spectral observations and statistics of galaxies with active nuclei" at Moscow State University (MSU) and became a Doctor of Sciences. In 1982, he was elected the Chair of the Department of Astrophysics and Theoretical Physics of the Armenian State Pedagogical University named after Khachatur Abovian. Arakelian wrote an extended review on “Clusters of galaxies” in the book Problems of Extragalactic Astronomy (1981). Prior to his death at the age of 54 on 20 January 1983 in Moscow, Arakelian devoted himself to research, publishing over 80 articles. Bibliography Arakelian, M. A. (1968) “Study of the luminosity