Fritz Zwicky

Fritz Zwicky was a Swiss astronomer. He worked most of his life at the California Institute of Technology in the United States of America, where he made many important contributions in theoretical and observational astronomy. He was the first to propose supernovas as giant explosions at the end of a star's life, and neutron stars as the remnants left over after supernovas. In 1933, Zwicky proposed that unseen dark matter would explain the much higher mass required to explain velocity dispersion in the Coma Cluster, compared to mass calculated from luminosity data.