Germany · Science / Astronomy. Chronological records rendered directly from the World History Database.
Walter Baade recognizes that Cepheids consist of at least two separate populations (classical Cepheids & Type II Cepheids). Classical Cepheids are younger and more massive population I stars, whereas Type II Cepheids are older fainter population. Resolves stars in the centre of the Andromeda galaxy for the first time, which led him to define distinct "populations" for stars (Population I and Population II)
Recalculates the size of the known universe, doubling the previous calculation made by Hubble in 1929, announces this finding to considerable astonishment at the 1952 meeting of the International Astronomical Union in Rome
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