Pulkovo Astronomical Observatory

the Main Astronomical Observatory of the Academy of Sciences of the USSR; a scientific research institution located 19 km south of the center of Leningrad in the Pulkovo hills (75 m above sea level). It was built according to the architectural design of A. P. Briullov and opened in 1839. It was organized by the prominent Russian scientist V. Ia. Struve, who was its first director (until the end of 1861 when he was replaced by his son, O. V. Struve). The observatory was equipped with the most advanced instruments, in particular a 38-cm refractor, at the time the largest in the world. The basic directions of work at the observatory concerned the determination of stellar coordinates and astronomical constants, such as precession, nutation, aberration, and refraction, and also the discovery and measurement of binary stars. Work at the observatory was also linked with geographical studies of the territory of Russia and with the development of ocean navigation. Absolute catalogs, which contained the most accurate positions of stars (at first 374 and then 558), were prepared for the periods 1845, 1865, 1885, 1905, and 1930. On the occasion of the observatory’s 50th anniversary, an astrophysical laboratory with a machine shop was built, and a 76-cm refractor—at that time the largest in the world—was set up. Astrophysical research progressed particularly rapidly after the appointment of F. A. Bredikhin (1890) as director of the observatory and the transfer from the Moscow observatory of A. A. Belopol’skii, a specialist in stellar spectroscopy and solar research. A large Littrow-system. spectrograph was erected in 1923, and in 1940 a horizontal solar telescope built at the Leningrad factory was set up. Work in astrophotography began in 1894 after a normal as-trograph was obtained, and in 1927 the observatory was improved with the addition of a zone astrograph, by means of which a stellar catalog of the near-polar region was compiled. Regular latitude observations for studying the motions of the earth’s poles began in 1904 with the zenith telescope constructed in the observatory shop. In 1920 the observatory began to transmit radio signals for accurate time measurement.

The observatory took an active part in basic geodesical work, specifically in the measurement of degrees of meridian arc along a path from the Danube to the Arctic Ocean completed in 1851, and in the triangulation of Spitsbergen in 1899–1901. Military geodesists and hydrographers were enrolled in basic studies at the observatory. The Pulkovo meridian, which passes through the center of the main building of the Observatory and is located 30° 19.6’ east of Greenwich, was the base line of all early geographic maps of Russia. Two branches were organized to study southern stars that were not visible at the latitude of Pulkovo: the astrophysical branch in Simeiz in the Crimea, on the basis of a private observatory presented to the Pulkovo Observatory by the amateur astronomer N. S. Mal’tsov in 1908; and the as-tronometric branch in Nikolaev in 1912 (formerly an observatory of the marine department, now called the Nikolaev Astronomical Observatory).

From the very beginning of the Great Patriotic War the observatory was subjected to heavy air raids and later, artillery bombardment. All the buildings were completely destroyed, and large instruments and a significant portion of the unique library were lost. Only several medium-sized instruments were saved. But even before the end of the war a government decision was made to reconstruct the observatory. In 1946, after the territory was cleared, reconstruction began, and in May 1954 the grand opening of the observatory was held, displaying not only the restored equipment but also a substantially increased number of instruments, workers, and research subjects. In particular, new departments (radio astronomy and astronomical instrument-making) were created, in conjunction with which a large optics machine shop was organized. The surviving old instruments were reinstalled after repair and modernization. New instruments include a 65-cm refractor, a horizontal meridian instrument, a photographic polar tube, a large zenith telescope, a stellar interferometer, two solar telescopes, a coronagraph, a large fan-shaped radiotelescope, and many laboratory instruments. The Nikolaev branch was preserved. (In 1945 the Simeiz branch was turned over to the Crimean Astrophysical Observatory of the Academy of Sciences of the USSR.) The Kislovodsk Mountain Astronomical Station was built, and a latitude-studies laboratory was organized in Blagoveshchensk on the Amur River. The observatory organized many expeditions for the study of longitude variations and the observation of the transits of Venus, solar eclipses, and the astroclimate. Since 1962 an expedition in Chile has been observing stars of the southern sky. Among the publications of the observatory are Trudy (Transactions; since 1893), Izvestiia (Proceedings; since 1907), Biulleteni sluzhby vremeni (Time Service Bulletins; since 1955), and Solnechnye dannye (Solar Data; since 1954).