Sergey Nikolayevich Blazhko (Russian: Серге́й Никола́евич Блажко́; November 17, 1870, Khotsimsk – February 11, 1956, Moscow) was a Russian and Soviet astronomer, a corresponding member of the Academy of Sciences of the Soviet Union (1929). He was a graduate of Moscow State University and held a number of positions there including head of the Moscow Observatory from 1920-1931. He discovered a secondary variation of the amplitude and period of some RR Lyrae stars and related pulsating variables, now known as the Blazhko effect.
Awards and honours
Laureate of the Stalin Prize, 2nd degree (1951)
Orders of Lenin (1944, 1953)
Orders of the Red Banner of Labour (1940, 1945)
Medal "For Valiant Labour in the Great Patriotic War 1941–1945" (1946)
Crater on the Moon and asteroid No. 2445 are named after Blazhko.