Swiss astronomer, born in Varna, Bulgaria, on 14 February 1898. He was an original thinker, with many important contributions in theoretical and observational astronomy. His father was the Bulgarian ambassador to Norway. He received an advanced education in mathematics and experimental physics at the Swiss Federal Institute of Technology in Zuerich and in 1925 emigrated to the United States to work at California Institute of Technology. He researched galaxies and produced a comprehensive catalogue of them. In 1934 he predicted the existence of neutron stars and black holes, formed by supernovae. In 1942 Zwicky was appointed Professor of Astronomy at California Institute of Technology and also worked as a research director for Aerojet Engineering Corporation and staff member of Mount Wilson and Palomar observatories. The Zwicky Museum at the Landesbibliothek, Glarus, houses many of his papers and scientific works. He died in Pasadena on 8 February 1974, and was buried in Mollis, Switzerland.