Zwicky, Fritz (tsvĭk`ē), 1898–1974, Swiss-American astrophysicist, b. Bulgaria, educated at Zürich. Associated with the California Institute of Technology after his arrival in the United States in 1925, he became professor of astrophysics in 1942 and emeritus professor in 1972. He discovered more than 120 supernovas supernova, a massive star in the latter stages of stellar evolution that suddenly contracts and then explodes, increasing its energy output as much as a billionfold.
..... Click the link for more information. and with Rudolf Minkowski and Walter Baade Baade, Walter (väl`tər bä`də), 1893–1960, German-born American astronomer.
..... Click the link for more information. he developed several models to explain their occurrence. Decades before the observational discovery of neutron stars neutron star, extremely small, extremely dense star, about double the sun's mass but only a few kilometers in radius, in the final stage of stellar evolution . Astronomers Baade and Zwicky predicted the existence of neutron stars in 1933.
..... Click the link for more information. , Zwicky suggested that the Crab Nebula in Taurus originated in a supernova. He is also known for his study of jet propulsion, cosmic rays, crystals, and slow electrons and ions in gases.

Zwicky, Fritz

(born Feb. 14, 1898, Varna, Bulg.—died Feb. 8, 1974, Pasadena, Calif., U.S.) Swiss astronomer and physicist. He received his Ph.D. from the Swiss Federal Institute of Technology and moved to the U.S. in 1925 to work at Caltech, where he remained until 1972. In 1934, with Walter Baade (1893–1960), he proposed that supernovas are a class of stellar explosions completely different from novas. He conducted an extensive search of neighbouring galaxies for supernovas and discovered 18; only about 12 had been recorded previously in the entire history of astronomy. In the years 1943–46, with Theodore von Kármán and others, he helped develop early jet-propulsion systems.