Ludwig von Struve (1858–1920): Development of Positional Astronomy at the Kharkiv Astronomical Observatory

An overview is given of the research work by Prof. Gustav Wilhelm Ludwig von Struve (in Russian, Lyudvig Ottovich Struve), a representative of the world-famous Struve dynasty of scholars. His work pertains to astrometry, a subfield of positional astronomy, traditionally studied by the Struves. Ludwig von Struve’s works on lunar eclipses and binary stars (in particular, the systems of η Cassiopeia and Procyon), their proper motions and positional determinations, stand out for their extraordinary methodicalness and meticulous processing. The greatest value is attached to those works by Struve where he calculates (being one the first researchers to do so) the speed of rotation of the Milky Way, refines the constant of precession, and determines the coordinates of the solar apex. At the Kharkiv Astronomical Observatory, Struve determined the positions of reference stars for the asteroid Eros, carries out long-term observations of circumpolar stars, and contributed to compiling a catalog of 779 zodiacal stars. He also organized an expedition of Kharkiv astronomers to observe the total solar eclipse of 1914. Struve’s works have been distinguished twice by the Russian Astronomical Society.