The Pulkovo Astronomical Observatory (Russian: Пу́лковская астрономи́ческая обсервато́рия, official name The Central Astronomical Observatory of the Russian Academy of Sciences at Pulkovo, Гла́вная (Пу́лковская) астрономи́ческая обсервато́рия Росси́йской акаде́мии нау́к), the principal astronomical observatory of the Russian Academy of Sciences, located 19 km south of Saint Petersburg on Pulkovo Heights 75 metres (246 ft) above sea level. It is part of the UNESCO World Heritage Site Historic Centre of Saint Petersburg and Related Groups of Monuments.
The observatory was opened in 1839. Originally, it was a brainchild of the German/Russian astronomer Friedrich Georg Wilhelm von Struve, who would become its first director (in 1861, his son Otto Wilhelm von Struve succeeded him). The architect was Alexander Bryullov. The observatory was equipped with the state-of-the-art devices, one of them being the a 15-inch (380 mm) aperture refractor, one of the large refractors in the world at that time (see Great Refractor). In 1885, the observatory was equipped with 30-inch (760 mm) refractor, which was one of the biggest refractors in the world, until the 36-inch (910 mm) telescope at the Lick Observatory in California a few years later, both of which were built by Alvan Clark & Sons in Massachusetts.
The principal line of work of the observatory consisted of determination of coordinates of stars and astronomical constants, such as precessions, nutations, aberrations and refractions, and also discovering and measuring double stars. Observatory’s activities have also been connected to the geographical study of the territory of Russia and development of navigation. The star catalogues, containing the most precise positions of 374, and then 558 stars, were made for the years 1845, 1865, 1885, 1905 and 1930.