Ivanov, Alexander Alexandrovich (astronomer)

Born April 4 [16], 1867 in St. Petersburg in a working class family. He studied at the St. Petersburg 8th gymnasium, which he graduated in 1885 with a gold medal. Due to material troubles in the family, he was forced to give lessons for earning from the third grade. After graduating from high school, he entered the mathematical department of the Faculty of Physics and Mathematics of St. Petersburg University . In the second year, he showed interest in lectures on astronomy , and then on higher geodesy , began to read special literature ^[2] .

After graduating from the university in 1889, he was left with him by Professor S.P. Glazenap to prepare for the professorship. In 1890-1901, at the invitation of A.F. Bredikhin , he worked at the Pulkovo Observatory as an observer on a large vertical circle. In 1895 he defended his master's thesis "Rotational motion of the Earth" (on the movement of the poles of the axis of rotation on the surface of the earth's spheroid) and received a master's degree in astronomy and geodesy. Since 1896 he was admitted to lecturing at the university as a private assistant professor . Continuing to work in Pulkovo, he was preparing a doctoral dissertation on the theme “The Theory of Precession,” which was defended in 1899 ^[2] .

In 1901 he left Pulkovo and moved to Petersburg to continue his teaching activities. Having received an offer from D. I. Mendeleev , he went to work in the Main Chamber of Weights and Measures headed by him, where he worked from 1902 to 1911 ^[2] . In 1908-1929, he was a professor at St. Petersburg (Leningrad) University , and from 1913-1919, he was also the director of the university observatory , where he established a regular publication of her works. In 1918-1919 - rector of the Petrograd University. In 1919-1930 - Director of the Pulkovo Observatory . Since 1930 - Deputy Director of the All-Union Scientific Research Institute of Metrology. D.I. Mendeleev .

The main scientific works are devoted to celestial mechanics and practical astronomy . According to observations on a large vertical circle in Pulkovo, he compiled three catalogs of absolute declination of stars, investigated the variability of Pulkovo latitude . He studied the resonant cases of the motion of small planets under the influence of the gravitational field of Jupiter . He studied the movement of the minor planet Gerda (according to observations of 1872-1934). He studied in detail the precession of the not quite spherical Earth under the influence of the attraction of the Moon and the Sun , and obtained the Earth's compression equal to 1: 297.2 - this is close to the modern value. Based on the analysis of gravity measurements at many points on the earth's surface, I concluded that the Earth’s northern and southern hemispheres are asymmetrical. He did much to improve the Soviet time service . Author of textbooks on general, spherical, practical, and theoretical astronomy. One of the founders of the Russian Astronomical Society and its chairman in 1906-1910 and 1913-1914.

• Kolchinsky I.G., Korsun A.A., Rodriguez M.G. Astronomers: A Biographical Reference. - 2nd ed., Revised. and additional .. - Kiev: Naukova Dumka, 1986. - 512 p.

• Profile of Alexander Alexandrovich Ivanov on the official website of the RAS
• Ivanov Alexander Alexandrovich