Laszlo Terkan

* Székesfehérvár, April 26, 1877 – † Budapest, March 26, 1940 / astronomer, ; Between 1900 and 1919, he worked at the Ógyalla Observatory ; ; He earned a teaching diploma in mathematics and physics at the Budapest University of Science and Technology, then a doctorate. In 1900, he became a calculator at the University of Budapest, but in the same year – on the recommendation of Radó Kövesligethy – he became an assistant professor at the Ógyalla Observatory, and from 1912 its observer. In the same year, he also earned a private teacher's qualification. During World War I, he served as a soldier and was only given leave twice. In 1920, he and Antal Tass moved the instruments and library of the Ógyalla Observatory, which had meanwhile become part of Czechoslovakia, to Budapest. From 1921, he worked at the Svábhegy Observatory. He retired as chief observer in 1935. He worked on several branches of astronomy (the motion of the Sun, the temperature of stars). He studied stars with variable brightness, and in the last years of his career he photographed asteroids. His main field of research was astrophotometry. He was very interested in determining the color of stars and the temperature measurements that could be derived from this. He wrote his doctoral dissertation on this subject in 1904, entitled “Determination of the Temperature of Fixed Stars”. The method he used provided good principles for red and yellow stars and was of pioneering significance at the time. He also performed interesting calculations for the binary star Beta Lyrae. Meanwhile, he also dealt with the issue of atmospheric light absorption and developed a method for determining the motion of the Sun in the Milky Way (the data he obtained are very close to the currently accepted values). His son-in-law László Kalmár (1905–1976) was a mathematician, university professor, and member of the Hungarian Academy of Sciences (1961).