Bilim insanlarının ülkelerarası yolculuğu: İstanbul Üniversitesi'nde dört yabancı astronom (1933-1958)

The aim of the present paper is to highlight the activities of four foreign astronomers who undertook the administration of the Astronomical Institute of the Faculty of Science, Istanbul University during the twenty-five years following the Atatürk University Reformation of 1933. The circumstances that led them to come to Turkey, their expectations, the evolution of the Astronomical Institute, and the scientific medium will also be studied. The four astronomers who were directors of the Institute and their terms of office are as follows: Erwin Finlay Freundlich (1933-37); Hans Rosenberg (1938-40); Thomas Royds (1942-47); Wolfgang Gleissberg (1941, 1948-58). Freundlich, Rosenberg and Royds were well established astronomers before being nominated as the chair of the Institute. The latter two came to Istanbul after they had retired. Gleissberg, however was a newly diplomed PhD holder when he arrived to Istanbul University in 1934, as the "scientific assistant" to Prof. Freundlich. He conducted all his research in Istanbul in the post-war years. This is the primary caracteristic which distinguishes him from the previous foreign chairmen at the Institute.